tag:blogger.com,1999:blog-15276994369580628992024-02-19T05:03:13.590-08:00Crack Banking Exambank exam, tnpsc, government exam, jobs, govt jobs, free mock test, free online coachingSenthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.comBlogger455125tag:blogger.com,1999:blog-1527699436958062899.post-72801961817104559032020-08-02T03:20:00.005-07:002021-08-23T01:12:20.524-07:00Data Communication<div dir="ltr" style="text-align: left;" trbidi="on">
<b>Data Communication</b> is the exchange of data in the form of 0s and 1s between a sender and receiver through some external transmission medium such as cable wire. Data communication aims in transfer of data and maintenance of data but here the actual information is not generated during the process.<br />
<br />
<b><span style="color: #0b5394;">Difference between Data and Information</span></b><br />
<br />
The two words Data and information may sound alike and used frequently by everyone but have a lot of differences in them.<br />
<br />
Data are plain facts and instructions represented in formalized manner for communication. When the data is processed organized and presented in a given context they become an information.<br />
<br />
<b><span style="color: #0b5394;">Characteristics of Data Communication system</span></b><br />
<br />
The effectiveness of data communication system depends on three characteristics.<br />
<br />
<b>Delivery: </b>The system must deliver data to the right destination.<br />
<br />
<b>Accuracy:</b>Data must be transferred accurately .<br />
<br />
<b>Timeliness:</b> Data must be transferred in a timely manner.<br />
<br />
<b><span style="color: #0b5394;">Components of Data Communication</span></b><br />
<br />
<b>Message: </b>This is the information to be delivered. It can be a image, text, audio, video, or a number.<br />
<br />
<b>The Sender: </b>The sender is a device or person who send the data. It can be sent using a phone, computer.<br />
<br />
<b>The receiver: </b>The receiver is a one who receives the data.<br />
<br />
<b>The medium: </b>The physical path by which the message travels from source to destination. Eg twisted pair,coaxial cable, fiber optics<br />
<br />
<b>Protocol:</b> It is the set of rules that govern data communication. It provide agreement between the sender and receiver.<br />
<br />
<b><span style="color: #0b5394;">Types of Data Transmission</span></b><br />
<ul style="text-align: left;">
<li>Analog Data Transmission</li>
<li>Digital Data Transmission</li>
</ul>
<b>Analog</b> data takes on continuous values on some interval. The most familiar example of analog data is audio signal. Frequency components of speech may be found between 20 Hz and 20 kHz.<br />
<br />
Another common example of analog data is video. The outputs of many sensors, such as temperature and pressure sensors, are also examples of analog data.<br />
<br />
<b>Digital</b> data takes on discrete values; eg. a computer’s output. – Analog transmission is a means of transmitting analog signals regardless of their content. The data may be analog or digital. – Digital transmission is the transfer of information through a medium in digital form. A digital signal can be transmitted only for a limited distance.<br />
<br />
<b><span style="color: #0b5394;">Transmission Medium</span></b><br />
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There are two basic categories of transmission media – guided and unguided media.<br />
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<b>Guided transmission</b> media use cabling system that guides the data signals along a specific path. Data signals are bound by the cabling system. Guided media is also known as bound media.<br />
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<b>Unguided transmission</b> media consists of a means for the data signals to travel but nothing to guide them along a specific path.<br />
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<b><span style="color: #0b5394;">Transmission Mode</span></b><br />
<br />
It is the direction of signal flow between two linked devices.<br />
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<b><span style="color: #0b5394;">Types of Transmission mode:</span></b><br />
<ul style="text-align: left;">
<li>Simplex</li>
<li>Half Duplex</li>
<li>Full Duplex</li>
</ul>
<b><span style="color: #0b5394;">Simplex</span></b><br />
<br />
Here the communication is unidirectional. Only one of the two devices can transmit data and other can receive data.<br />
<br />
<b><span style="color: #0b5394;">Half Duplex:</span></b><br />
<br />
In half duplex both the devices can transmit data and receive data but not at the same time.<br />
<br />
Eg: Walkie talkie<br />
<br />
<b><span style="color: #0b5394;">Full Duplex:</span></b><br />
<br />
In full duplex both the devices can send and receive data at the same time.<br />
<br />
Eg: mobile phone.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-88412062745618091162020-08-02T03:00:00.005-07:002021-08-23T01:12:20.525-07:00Useful Microsoft Word Keyboard Shortcuts: CTRL A-Z and Others<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: #0b5394;">CTRL Shortcuts from A-Z:</span></b><br />
<ul style="text-align: left;">
<li>CTRL + A = Select text</li>
<li>CTRL + B = Bold text</li>
<li>CTRL + C = Copy text</li>
<li>CTRL + D = Open font formatting window</li>
<li>CTRL + E = Center text</li>
<li>CTRL + F = Find a phrase</li>
<li>CTRL + G = Go To a specific page or bookmark</li>
<li>CTRL + H = Replace text with another text or replace text with different formatting</li>
<li>CTRL + I = Italicize text</li>
<li>CTRL + J = Justify text</li>
<li>CTRL + K = Open Insert Hyperlink window</li>
<li>CTRL + L = Left align text</li>
<li>CTRL + M = Indent a paragraph from the left</li>
<li>CTRL + N = Open new Word document</li>
<li>CTRL + O = Open an existing Word document</li>
<li>CTRL + P = Print Word document</li>
<li>CTRL + Q = Remove paragraph formatting</li>
<li>CTRL + R = Right align text</li>
<li>CTRL + S = Save Word document</li>
<li>CTRL + T = Create a hanging indent</li>
<li>CTRL + U = Underline text</li>
<li>CTRL + V = Paste text</li>
<li>CTRL + W = Close Word document</li>
<li>CTRL + X = Cut text</li>
<li>CTRL + Y = Redo an action previously undone OR repeat an action</li>
<li>CTRL + Z = Undo a previous action</li>
</ul>
<b><span style="color: #0b5394;">CTRL + SHIFT Shortcuts From A-Z:</span></b><br />
<ul style="text-align: left;">
<li>CTRL + SHIFT + C =Copy Formats</li>
<li>CTRL + SHIFT + D = Double Underline text</li>
<li>CTRL + SHIFT + E = Track changes</li>
<li>CTRL + SHIFT + F = Change the font</li>
<li>CTRL + SHIFT + H = Apply hidden text formatting</li>
<li>CTRL + SHIFT + K = Format letters as small capitals</li>
<li>CTRL + SHIFT + L = Apply the List style</li>
<li>CTRL + SHIFT + M = Remove a paragraph indent from the left</li>
<li>CTRL + SHIFT + N = Apply the Normal Style</li>
<li>CTRL + SHIFT + P = Change the font size</li>
<li>CTRL + SHIFT + Q = Change the selection to the Symbol font</li>
<li>CTRL + SHIFT + S = Apply a style</li>
<li>CTRL + SHIFT + T= Reduce a hanging indent</li>
<li>CTRL + SHIFT + V =Paste Formats</li>
<li>CTRL + SHIFT + W = Underline words but not spaces</li>
</ul>
<b><span style="color: #0b5394;">Other CTRL Shortcuts</span></b><br />
<ul style="text-align: left;">
<li>CTRL + ] = Increase size of selected text by one point</li>
<li>CTRL + [ = Decrease size of selected text by one point</li>
<li>CTRL + SHIFT+ > = Increase font size</li>
<li>CTRL + SHIFT + < = Decrease font size</li>
<li>CTRL + 1 = Single-space lines</li>
<li>CTRL + 2 = Double-space lines</li>
<li>CTRL + 5 = 1.5 space lines</li>
<li>CTRL + 0 = Add/remove one line space preceding a paragraph</li>
<li>CTRL + Left Arrow = Move one word to the left</li>
<li>CTRL + Right Arrow = Move one word to the right</li>
<li>CTRL + Up Arrow = Move one paragraph up</li>
<li>CTRL + Down Arrow =Move one paragraph down</li>
<li>CTRL + Page Up = Go to the top of previous page</li>
<li>CTRL + Page Down = Go to the top of next page</li>
<li>CTRL + END = Go to the end of document</li>
<li>CTRL + HOME = Go to the beginning of document</li>
<li>CTRL + ENTER = Page break</li>
<li>CTRL + DELETE = Delete one word to the right</li>
<li>CTRL + BACKSPACE = Delete one word to the left</li>
<li>CTRL + TAB = Insert a Tab character</li>
<li>CTRL + ALT + S = Copyright symbol</li>
<li>CTRL + ALT + R = Registered trademark symbol</li>
<li>CTRL + ALT + T = Trademark symbol</li>
<li>CTRL + ALT + M = Insert a comment</li>
<li>CTRL + ALT + I = Switch in or out of print preview</li>
</ul>
There are more CTRL shortcuts than what I have mentioned above. Since you have plenty of CTRL shortcuts to digest already I thought it would be best to not include anymore. Hope these shortcuts are helpful to you and hope you can apply them the next time you use Microsoft Word.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-24056284423906250902020-08-02T02:57:00.002-07:002021-08-23T01:12:20.519-07:00Computer Keyboard Shortcut Keys<div dir="ltr" style="text-align: left;" trbidi="on">
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Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-37490795072636274202020-08-02T02:51:00.000-07:002021-08-23T01:12:20.521-07:00Important MS Office Word Key Board Shortcuts<div dir="ltr" style="text-align: left;" trbidi="on">
Before reading this article, please open a page in MS Word in your Computer. Type or copy paste some contents into the page.<br />
<br />
Now try the following short cuts one by one and realize the operation. Now think how we can keep it in our memory so that we can answer the questions related to shortcuts in Bank, Insurance and other Govt. exams. Most of them are already known to you and a few are new.<br />
<br />
<b><span style="color: #0b5394;">DOCUMENT HANDLING</span></b><br />
<ul style="text-align: left;">
<li>Create New document- Ctrl+N</li>
<li>Open document- Ctrl+O </li>
<li>Close document Window- Ctrl+W</li>
<li>Save document- Ctrl+S</li>
<li>Save as- F12</li>
<li>Print document or Open Print preview- Ctrl+P</li>
<li>Switch between multiple Word documents- Ctrl+F6 </li>
</ul>
<b><span style="color: #0b5394;">DOCUMENT VIEW</span></b><br />
<ul style="text-align: left;">
<li>Switch to Print Layout view- Alt+Ctrl+P</li>
<li>Switch to Outline view- Alt+Ctrl+O</li>
<li>Switch to Draft view (used to see Normal view)- Alt+Ctrl+N </li>
<li>Zoom in and zoom out- Ctrl+Scroll Mouse </li>
</ul>
<b><span style="color: #0b5394;">CURSOR MOVEMENT</span></b><br />
<ul style="text-align: left;">
<li>Jump one character to the Left / to the Right- Arrow Left/Arrow Right </li>
<li>Jump one word to the left / to the right- Ctrl+Arrow Left/Ctrl+Arrow Right </li>
<li>Jump to the End of a line / Beginning of a line- End/Home </li>
<li>Jump one Line down / one Line down- Arrow Down/Arrow Up </li>
<li>Jump one Paragraph down / one Paragraph up- Ctrl+Arrow Down/ Ctrl+Arrow Up </li>
<li>Jump one Screen down/ one Screen up- Page Down/Page Up </li>
<li>Jump to End / to Beginning of document- Ctrl+End/Ctrl+Home </li>
<li>Go back to previously edited location in document (up to 4 places)- Alt+Ctrl+Z </li>
</ul>
<b><span style="color: #0b5394;">TEXT SELECTION</span></b><br />
<ul style="text-align: left;">
<li>Extend selection one character to the Right / to the Left- Shift+Arrow Right/Left</li>
<li>Extend selection to the End / to Beginning of a line- Shift+End/Shift+Home </li>
<li>Extend selection one line Down / one line Up- Shift+Arrow Down/Up</li>
<li>Extend selection one screen down / one screen up- Shift+Page Down/Up </li>
<li>Extend selection to end / to beginning of document- Ctrl+Shift+End/Home </li>
<li>Extend selection to end / to beginning of visible window- Alt+Ctrl+Shift+Page Down/Up</li>
<li>Extend selection to entire document- Ctrl+A</li>
</ul>
<b><span style="color: #0b5394;">TEXT STYLE</span></b><br />
<ul style="text-align: left;">
<li>Decrease / Increase font size one value- Ctrl+Shift+</li>
<li>Apply/remove Bold- Ctrl+B</li>
<li>Apply/remove Italic- Ctrl+I </li>
<li>Apply/remove Underline- Ctrl+U</li>
<li>Apply/remove subscript –Ctrl+=</li>
<li>Apply/remove superscript- Ctrl+Shift+=</li>
<li>Apply/remove Double-underline- Ctrl+Shift+D</li>
<li>Apply/remove Words underline (only words, no spaces)- Ctrl+Shift+W</li>
<li>Apply/remove All capitals– Ctrl+Shift+A</li>
<li>Apply/remove Small capitals- Ctrl+Shift+K</li>
<li>Change between All upper, First letter upper and All lower-case- Shift+F3</li>
<li>Reveal Formatting (style of the fonts and paragraph)- Shift+F1</li>
<li>Apply/remove Highlight Text- Ctrl+Alt+H </li>
</ul>
<b><span style="color: #0b5394;">PARAGRAPH STYLE</span></b><br />
<ul style="text-align: left;">
<li>Right-align paragraph- Ctrl+R</li>
<li>Left-align paragraph- Ctrl+L</li>
<li>CEnter-align paragraph –Ctrl+E</li>
<li>Justify-align paragraph- Ctrl+J </li>
<li>Increase hanging indenT (Spacing at the beginning of a paragraph) – Ctrl+T</li>
<li>Decrease hanging indenT(Spacing at the beginning of a paragraph)- Ctrl+Shift+T</li>
<li>Set line-spacing to single-space- Ctrl+1</li>
<li>Set line-spacing to double-space- Ctrl+2 </li>
<li>Set line-spacing to 1.5- Ctrl+5</li>
<li>Add or remove one line space preceding a paragraph – Ctrl+0 (zero) </li>
</ul>
<b><span style="color: #0b5394;">UNDO REDO</span></b><br />
<ul>
<li>Undo the last action- Ctrl+Z</li>
<li>Redo the last action- Ctrl+Y</li>
</ul>
<b><span style="color: #0b5394;">COPY PASTE</span></b><br />
<ul style="text-align: left;">
<li>Copy selected text or object- Ctrl+C</li>
<li>Cut selected text or object- Ctrl+X </li>
<li>Paste selected text or object- Ctrl+V </li>
<li>Copy text format (Size, Font and Style of the Text)-Ctrl+Shift+C</li>
<li>Paste text format (Size, Font and Style of the Text)- Ctrl+Shift+V</li>
</ul>
<b><span style="color: #0b5394;">INSERT SYMBOL/OBJECT</span></b><br />
<ul style="text-align: left;">
<li>Insert Symbol Menu – Alt+N+U</li>
<li>Insert Copyright (©) symbol- Alt+Ctrl+C</li>
<li>Insert Registered Trademark (®) symbol- Alt+Ctrl+R</li>
<li>Insert trademark symbol (™) symbol- Alt+Ctrl+T</li>
<li>Insert horizontal ellipsis (…) symbol – Alt+Ctrl+.</li>
<li>Insert paragraph break- Enter</li>
<li>Insert line break without breaking paragraph- Shift+Enter</li>
<li>Insert page break- Ctrl+Enter</li>
<li>Insert a Footnote- Alt+Ctrl+F</li>
<li>Insert an EnDnote- Alt+Ctrl+D</li>
<li>Insert a HyperlinK– Ctrl+K</li>
</ul>
<b><span style="color: #0b5394;">FIND AND REPLACE</span></b><br />
<ul style="text-align: left;">
<li>Find a word- Ctrl+F</li>
<li>Find a word and Replace with another word- Cntrl+H</li>
</ul>
<b><span style="color: #0b5394;">DELETE</span></b><br />
<ul style="text-align: left;">
<li>Delete one character to the right / to the left (or delete selection)- Delete/Backspace</li>
<li>Delete one word to the right / to the left- Ctrl+Delete/Ctrl+Backspace</li>
</ul>
</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com1tag:blogger.com,1999:blog-1527699436958062899.post-44491022044814598662020-08-02T02:43:00.005-07:002021-08-23T01:12:20.522-07:00Microsoft Office<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: #38761d;">MS Word</span></b><br />
<br />
MSWORD programme is called a word-processing package. This means that it is useful for typing and storing letters, articles and anything that consists mainly of words. Many of Word’s most powerful formatting and processing tools may remain hidden until you discover where they are and learn how to use them. MS Word administrative documents are created and stored as files where information can be entered, edited and formatted and saved electronically. MS Word can be used to type letters, memos, notices, fax cover sheets and envelopes for mailing or distribution. Newsletters, brochures and books can also be created using MS Word. Additional graphs, photographs, charts, drawings and tables can be inserted into a Word document to further illustrate and enhance administrative documents. Microsoft Word’s native file formats are denoted either by a .doc or .docx file extension.<br />
<br />
<b><span style="color: #0b5394;">Function Keys:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
<br />
<table><tbody>
<tr>
<th style="width: 30%;">Function Key</th>
<th style="width: 70%;">Description</th>
</tr>
<tr>
<td>F1</td>
<td>Get help or visit Microsoft office Online</td>
</tr>
<tr>
<td>F2</td>
<td>Move text or graphic</td>
</tr>
<tr>
<td>F4</td>
<td>Repeat the last action</td>
</tr>
<tr>
<td>F5</td>
<td>Choose the Go To command (Home tab)</td>
</tr>
<tr>
<td>F6</td>
<td>Go to the nest pane or frame</td>
</tr>
<tr>
<td>F7</td>
<td>Choose the spelling command (Review tab)</td>
</tr>
<tr>
<td>F8</td>
<td>Extend a selection</td>
</tr>
<tr>
<td>F9</td>
<td>Update the selected fields</td>
</tr>
<tr>
<td>F10</td>
<td>Show key tips</td>
</tr>
<tr>
<td>F11</td>
<td>Go to the nest field</td>
</tr>
<tr>
<td>F12</td>
<td>Choose the Save As command (Microsoft Office Button)</td>
</tr>
</tbody></table>
<br />
<b><span style="color: #0b5394;">Control Keys + Function keys:</span></b><br />
<br />
<table><tbody>
<tr>
<th style="width: 30%;">Control Keys + Function keys</th>
<th style="width: 70%;">Description</th>
</tr>
<tr>
<td>Ctrl+F2</td>
<td>Choose the print preview command (Microsoft office Button)</td>
</tr>
<tr>
<td>Ctrl+F3</td>
<td>Cut on the spike</td>
</tr>
<tr>
<td>Ctrl+F4</td>
<td>Close the window</td>
</tr>
<tr>
<td>Ctrl+F6</td>
<td>Go to the next window</td>
</tr>
<tr>
<td>Ctrl+F9</td>
<td>Insert an empty field</td>
</tr>
<tr>
<td>Ctrl+F10</td>
<td>Maximise the document window</td>
</tr>
<tr>
<td>Ctrl+F11</td>
<td>Lock a field</td>
</tr>
<tr>
<td>Ctrl+F12</td>
<td>Choose the Open command (Microsoft Office Button)</td>
</tr>
</tbody></table>
<br />
<b><span style="color: #0b5394;">Basic Keys Common Tasks:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
<table><tbody>
<tr>
<th style="width: 30%;">Basic Keys Common Tasks</th>
<th style="width: 70%;">Description</th>
</tr>
<tr>
<td>Ctrl + Shift + Spacebar</td>
<td>Create a non breaking space</td>
</tr>
<tr>
<td>Ctrl + B</td>
<td>Make letters bold</td>
</tr>
<tr>
<td>Ctrl + I</td>
<td>Make letters italic</td>
</tr>
<tr>
<td>Ctrl + U</td>
<td>Make letters underline</td>
</tr>
<tr>
<td>Ctrl + Shift+ </td>
<td>Decrease font size one value</td>
</tr>
<tr>
<td>Ctrl + Shift +</td>
<td>Increase the font size one value</td>
</tr>
<tr>
<td>Ctrl + [</td>
<td>Increase the font size by 1 point</td>
</tr>
<tr>
<td>Ctrl + ]</td>
<td>Decrease the font size by 1 point</td>
</tr>
<tr>
<td>Ctrl + Spacebar</td>
<td>Remove paragraph or character formatting</td>
</tr>
<tr>
<td>Ctrl + C</td>
<td>Copy the selected text or object</td>
</tr>
<tr>
<td>Ctrl + X</td>
<td>Cut the selected text or object </td>
</tr>
<tr>
<td>Ctrl + V</td>
<td>Paste text or an object</td>
</tr>
<tr>
<td>Ctrl + Alt + V</td>
<td>Paste special</td>
</tr>
<tr>
<td>Ctrl + Shift + V</td>
<td>Paste formatting only</td>
</tr>
<tr>
<td>Ctrl + Z</td>
<td>Undo the last action</td>
</tr>
<tr>
<td>Ctrl + Y</td>
<td>Redo the last action</td>
</tr>
</tbody></table>
<br />
<br />
<b><span style="color: #38761d;">Ms Excel</span></b><br />
<br />
Spreadsheets, files and memos are necessary documents in most businesses. Until computers became part of the typical business office, these types of records were created on paper and stored in metal filing cabinets. Today, these records are created using computer software programs such as Microsoft Word or Excel and filed electronically.Microsoft Excel is a spreadsheet program used to store and retrieve numerical data in a grid format of columns and rows. Excel is ideal for entering, calculating and analyzing company data such as sales figures, sales taxes. Excel can store and calculate the data as directed using existing or new data.<br />
<br />
<b><span style="color: #0b5394;">Shortcut Keys of MS-Excel:</span></b><br />
<br />
<table><tbody>
<tr>
<th style="width: 30%;">Key</th>
<th style="width: 70%;">Description</th>
</tr>
<tr>
<td>F2</td>
<td>Edit the selected cell</td>
</tr>
<tr>
<td>F5</td>
<td>Go to a specific cell</td>
</tr>
<tr>
<td>F7</td>
<td>Spell check selected text and/or document</td>
</tr>
<tr>
<td>F11</td>
<td>Create chart</td>
</tr>
<tr>
<td>Ctrl + Shift + ; </td>
<td>Enter the current time</td>
</tr>
<tr>
<td>Ctrl + ;</td>
<td>Enter the current date</td>
</tr>
<tr>
<td>Shift + F3</td>
<td>Open the Excel formula window</td>
</tr>
<tr>
<td>Shift + F5</td>
<td>Bring up search box</td>
</tr>
<tr>
<td>Ctrl + A</td>
<td>Select all contents of the worksheet</td>
</tr>
<tr>
<td>Ctrl + B</td>
<td>Bold highlighted selection</td>
</tr>
<tr>
<td>Ctrl + I</td>
<td>Italic highlighted selection</td>
</tr>
<tr>
<td>Ctrl + U</td>
<td>Underline highlighted selection</td>
</tr>
<tr>
<td>Ctrl + P</td>
<td>Bring up the print dialog box to begin printing</td>
</tr>
<tr>
<td>Ctrl + Z</td>
<td>Undo last action</td>
</tr>
<tr>
<td>Ctrl + F9</td>
<td>Minimise current workbook</td>
</tr>
<tr>
<td>Ctrl + F10</td>
<td>Maximise currently selected workbook</td>
</tr>
<tr>
<td>Ctrl + F6</td>
<td>Switch between open workbooks/window</td>
</tr>
<tr>
<td>Ctrl + page up</td>
<td>Move between Excel worksheet in the same Excel document.</td>
</tr>
<tr>
<td>Ctrl + Page Down</td>
<td>Move between Excel worksheets in the same Excel document</td>
</tr>
<tr>
<td>Ctrl + Tab</td>
<td>Move between two or more open Excel files</td>
</tr>
<tr>
<td>Alt + =</td>
<td>Create a formula to sum all of the above cells</td>
</tr>
<tr>
<td>Ctrl + ’</td>
<td>Insert the value of the above cell into cell currently selected.</td>
</tr>
<tr>
<td>Ctrl + Arrow key</td>
<td>Move to next section to text</td>
</tr>
<tr>
<td>Ctrl + Space</td>
<td>Select entire column</td>
</tr>
<tr>
<td>Shift + Space</td>
<td>Select entire row</td>
</tr>
</tbody></table>
<b><span style="color: #38761d;"><br /></span></b>
<b><span style="color: #38761d;">MS-Powepoint</span></b><br />
<br />
It is a PowerPoint that anyone can use. You can draw pictures with it. MS PowerPoint is a software application that has replaced 35mm slide shows of the past. One creates this presentation tool by creating a series of horizontally formatted “slides”.<br />
<br />
Video and audio can also be added here. The uses of PowerPoint seem to be endless. Almost any presentation can be enhanced through visual and sound effects, and this application has become the standard tool to do so.<br />
<br />
PowerPoint presentations consist of a number of individual pages or “slides”. Microsoft PowerPoint’s native file formats are denoted either by a .ppt or .pptx file extension.<br />
<br />
<b><span style="color: #38761d;">MS Access</span></b><br />
<br />
MS-Access is a database management tool of Microsoft. This is given with MS-Office package. There is need for a database management tools like Access for all corporate and private organizations etc., where large amount of data to be handled.<br />
<br />
<b><span style="color: #0b5394;">Advantages of MS-Access:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
MS-Access has very easy operating procedure compared to other database management tools that are available. Also this is fairly cheaper and can be installed in most of the computers. Table creation is simply done by design or wizard options. Data entered and stored in MS-Access can easily be exported or pasted into spreadsheets or statistical software for further analysis.<br />
<br />
As part of the MS Office Suite, MS Access integrates seamlessly with MS Word and Excel. Any data stored in MS-Access can be easily used throughout the MS-Office applications.In general users with little programming knowledge can use MS Access effectively.<br />
<br />
There are useful menus like “File, Edit etc., to provide users a very effective usage of good database management. There is no console window, no complex Syntaxes, and no complex queries for Ms-Access. These are common characteristics of most of the database management tools. So MS-Access is a very effective database management tool without any normally occurring distractions of a common database management tool.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-9623195775294484942020-08-02T01:43:00.002-07:002021-08-23T01:12:20.518-07:00INTERNET SECURITY THREATS<div dir="ltr" style="text-align: left;" trbidi="on">
Virus : It is a program written to attack the normal operation of a Computer, normally which affects the programs associated with the Operating System or Device Driver. Usually it is transmitted through the executable files. Viruses can run only if the affected program is running. These are the most well-known internet security threat.<br />
<br />
Worms: Similar to viruses but much more dangerous. They spread rapidly by accessing your email address book and automatically forwarding themselves to every address it has.<br />
<br />
<b><span style="color: #0b5394;">Trojan:</span></b> It is a program written to make your Computer unprotected so that hackers can reach the data in your computer. Trojans are self-sufficient programs. These programs give unrestricted access of computers to attackers.<br />
<br />
<b><span style="color: #0b5394;">Spyware:</span></b> It is a software that secretly collects user information while on the internet. Spyware can capture information like web browsing habits, email messages, usernames and passwords, and credit card information.<br />
<br />
<b><span style="color: #0b5394;">Adware: </span></b>This program launches the advertisements in the form of pop ups. Usually the add words are based on the internet behavior of the user.<br />
<br />
<b><span style="color: #0b5394;">Spam: </span></b>These are unwanted emails. In other words we can call them as unsolicited promotional mail.<br />
<br />
<b><span style="color: #0b5394;">Phishing: </span></b>This is acquiring the personal and sensitive information of a person through official looking emails. Users of online banking and e-commerce websites are more prone to this attack.<br />
<br />
<b><span style="color: #0b5394;">Pharming:</span></b> More advance method of Phishing in which the attackers create duplicate or similar looking website of other companies, to attract the customers and steal the data.<br />
<br />
<b><span style="color: #0b5394;">Cookies:</span></b> These are program or information secretly stored in a computer especially the internet browser, which allows other users to monitor the internet activities of a person. These programs usually monitor the browsing nature of person so that the companies can create better marketing strategies.<br />
<br />
<span style="color: #0b5394;"><b>Mail Bomb:</b> </span>An excessively large email (typically many thousands of messages) or one large message sent to a user’s email account. This is done to crash the system and prevent genuine messages from being received.<br />
<br />
<b><span style="color: #0b5394;">Scareware:</span></b> A common trick cyber criminals use to make users think that their computer has become infected with malware to get them to purchase a fake application. Often the fake application that the user is tricked into purchasing is actually a malicious program which can disable real antivirus software and wreak havoc on a user’s machine.<br />
<br />
<b><span style="color: #0b5394;">Sniffers:</span></b> A software program used to monitor the traffic in a network. The hackers may use the sniffed data to access important confidential data.<br />
<br />
<b><span style="color: #0b5394;">Rootkit:</span></b> A program designed to hide objects such as processes, files or Windows registry entries (often including its own). This type of software is not malicious in itself, but is used by hackers to cover their tracks in previously compromised systems. There are types of malware that use rootkits to hide their presence on the system.<br />
<br /></div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-91556273306003302282020-08-02T01:40:00.002-07:002021-08-23T01:12:20.526-07:00Internet Protocol- IPv4 & IPv6<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: #0b5394;">Internet Protocol</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
Internet Protocol is a set of technical rules and guidelines that defines how different computers communicate over a Computer Network. IP address is a number used by different computers and servers in the Internet to communication each other. Without IP address, computers will not be able to communicate and send data each other. It is essential to the infrastructure of the web. It is like an Address is required to identify a Person.<br />
<br />
<b><span style="color: #0b5394;"> IPv4 (Internet Protocol Version 4)</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
IPv4 was the first version of Internet Protocol to be widely used, and accounts for most of today’s Internet traffic. There are just over 4.3 billion IPv4 addresses. IPv4 has the limitation of lesser number of addresses, so it can address only limited number of Computers.<br />
<br />
<b><span style="color: #0b5394;"> IPv6 (Internet Protocol Version 6)</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
IPv6 is a newer numbering system that provides a much larger address pool than IPv4. It was deployed in 1999 and should meet the world’s IP addressing needs well into the future. It is replacing IPv4 to accommodate the growing number of networks worldwide and help solve the IP address exhaustion problem due to increased number of Mobile Computing Devices. IPv6 is referred as the Next Generation Internet Standard.<br />
<br />
<b><span style="color: #38761d;">At present the following websites are using IPv6: Facebook, Google, Yahoo, Wikipedia, You tube, etc.</span></b><br />
<br />
The world IPv6 Launch Day was celebrated across the world on 6th June 2012.<br />
<br />
<b><span style="color: #3d85c6;"> Differences Between IPv4 and IPv6</span></b><br />
<ul style="text-align: left;">
<li>IPv4 uses four 1 byte decimal numbers, separated by a dot (i.e. 192.168.1.1),</li>
<li>IPv6 uses hexadecimal numbers that are separated by colons (i.e. fe80::d4a8:6435:d2d8:d9f3b11).</li>
<li>Packet size in IPv4 is 576 bytes</li>
<li>Packet size in IPv6 is 1280 bytes</li>
<li>Broadcast feature is available in IPv4</li>
<li>Broadcast feature is not available in IPv6</li>
<li>IPv6 is more compatible to mobile networks than IPv4</li>
<li>IPv6 is used by less than 1% of the networks, while IPv4 is still in use by 99%</li>
<li>Communication Trace feature is available in both IPv4 and IPv6</li>
</ul>
<b><span style="color: #0b5394;">Advantages of IPv6 over IPv4</span></b><br />
<ul style="text-align: left;">
<li>Security</li>
<li>Auto configuration</li>
<li>Simplified Header format with better Quality of Service (QoS)</li>
<li>IP Host Mobility</li>
<li>IPv6 has been designed with many new features which make it possible to develop innovative applications which are not easily possible in the current IPv4 protocol</li>
<li>The limit of payload size is not there in IPv6 and its size can be as large as possible depending upon the Maximum Transmission Unit</li>
</ul>
<b><span style="color: #0b5394;"> IPv6 in India</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
The First Roadmap (Version- I) was released on 20th July, 2010.<br />
<br />
<b>The Guidelines of The First Roadmap were:</b><br />
<ul style="text-align: left;">
<li>All Major Service Providers (having at least 10,000 internet customers or STM-1 bandwidth) will target to handle IPv6 traffic and offer IPv6 services by December-2011</li>
<li>All Central and State Government Ministries and Departments, including its PSUs, shall start using IPv6 services by March-2012.</li>
<li>Creation of IPv6 Task Force</li>
</ul>
The objective of the recently published (March 2013) IPv6 Deployment Roadmap Version II by Ministry of Communications & Information Technology, Department of Telecommunications, Government of India.<br />
<br />
<b>“ To achieve substantial transition to new Internet Protocol (IPv6) in the country in a phased and time bound manner by 2020 and encourage an ecosystem for provision of a significantly large bouquet of services on IP platform.”</b><br />
<br />
<b><span style="color: #0b5394;"> As on date (publishing date of this article) the Per-Country IPv6 adoption date of India is 0.65%, while that of United States and France are 14.74% and 15.91% respectively.</span></b><br />
<br />
You may visit the following link published by Google to collect the details about the statistics.<br />
<br />
<b><span style="color: #0b5394;">IPv6 Country Wide Adoption Statistics</span></b><br />
<br />
To get more information about IPv6 adoption in India, please go through various IPv6 Roadmap Versions published by Ministry of Communications & Information Technology, GOI.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-92088828512136319992020-08-02T01:33:00.004-07:002021-08-23T01:12:20.526-07:00Automated Teller Machine<div dir="ltr" style="text-align: left;" trbidi="on">
Automated Teller Machines (ATMs) are considered as the most influential technological innovation of 21st century. An Automated Teller Machine is a Telecommunication Device installed in the public so that people have access to their money without going to the Bank. The customer is identified by entering a Plastic Card with a Magnetic Strip or Chip in the ATM. All the information regarding the customer are available in the card. The customer needs to enter some PIN (Personal Identification Number) to perform the Transactions.<br />
<br />
ATM is a data terminal which connects to the Bank Computer Network to retrieve the information through the Host Computer. The ATMs are connected to the Bank Computer Network using Internet or Telephone Lines.<br />
<br />
There are provisions to count the notes and measure the thickness of the bundle of notes to ensure the correctness of the number of notes dispensed to the Customer.<br />
<br />
There are three input devices in an ATM. They are Card Reader, a Key Pad and a Web Camera. The Card reader is used to get the information encoded in the magnetic strip of the ATM Card. Keypad allows us to enter the PIN number and other inputs to process or cancel a transaction. The pictures and videos captured in the Web Camera are used for security purpose. Most of the time, these videos will be recorded using a Digital Video Recorder.<br />
<br />
<b>The output devices in an ATM are:</b> Speaker, LCD/CRT Screen, Receipt Printer and Cash Dispenser.<br />
<br />
<b><span style="color: #0b5394;">Most of the Modern ATMs contains a Secure Crypto Processor along with the CPU for the secure transmission and reception of the data from and into the ATM. Encrypting PIN Pad is used to secure the PIN numbers entered by the Customer. The encryption algorithm used for this purpose is DES 3 (Data Encryption Standard 3)</span></b><br />
<br />
The Operating System used in the ATMs are mostly Microsoft Windows XP, 7, 8 or Linux variants.<br />
<br />
<b>Time Out:</b> It is a security feature enabled in ATMs to enter the PIN number within a stipulated time. If the customer fails to enter the PIN within this time, the transaction will be cancelled.<br />
<br />
<b>Invalid PIN: </b>This is another security feature enabled in ATMs to prevent unauthorized usage of ATM cards. If a person fails to enter the correct PIN within 3 attempts, the card will be disabled for next 24 hours.<br />
<br />
In some countries the Modern ATMs has most advanced security systems like biometric, facial, retinal identification systems to avoid unauthorized access to Bank accounts.<br />
<br />
<b><span style="color: #0b5394;">How an ATM Works?</span></b><br />
<br />
In order to access various accounts, ATM computers are connected to complex interbank networks, which allow customers from many different banks to access their accounts through the machine.<br />
<br />
When an ATM transaction is processed, the machine starts communication with the network of the banks to begin the authorization process. The ATM machine has a unique TID (terminal ID number). This is how the networks allow the transaction to be completed. This TID along with other identifying information lets the cardholder’s bank know that the transaction is taking place on that particular ATM.<br />
<br />
Now the ATM can connect to the networks through a processing center and then to the cardholder’s bank. If there are sufficient funds in the ATM cardholders account for the withdrawal request, the transaction will be completed. Once transactions are approved the ATM receives the authorization and dispenses the cash requested. Based on the cash dispensed by the ATM, an equal amount is deposited to the Bank which hosts the ATM and from there to the ATM. The ATM can also be used if someone just wants to check their account balance or transfer funds before or after withdrawing cash.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-15214969516245489672020-08-02T01:31:00.002-07:002021-08-23T01:12:20.519-07:00Microsoft Windows<div dir="ltr" style="text-align: left;" trbidi="on">
Microsoft Windows is a group of OSs manufactured by Microsoft. Windows is available in 32 and 64-bit versions. Windows OSs constitute client as well as server versions. Similar to other operating systems, Windows makes a computer system user-friendly by providing a graphical display and organizing information so that it can be easily accessed.<br />
<br />
Estimates suggest that 90% of personal computers use the Windows operating system. Microsoft introduced the operating system in 1985 and it has continued to be widely used despite competition from Apple’s Macintosh operating system.<br />
<br />
<b><span style="color: #0b5394;">Family of Microsoft Windows</span></b><br />
<br />
Windows has seen nine major versions since its first release in 1985. Here’s a brief look at the history of Windows.<br />
<br />
<b><span style="color: #0b5394;">Windows 1</span></b><br />
<br />
This is where it all started for Windows. The original Windows 1 was released in November 1985 and was Microsoft’s first true attempt at a graphical user interface in 16-bit.<br />
<br />
<b><span style="color: #0b5394;">Windows 2</span></b><br />
<br />
Two years after the release of Windows 1, Microsoft’s Windows 2 replaced it in December 1987. The big innovation for Windows 2 was that windows could overlap each other, and it also introduced the ability to minimize or maximize .<br />
<br />
<b><span style="color: #0b5394;">Windows 3</span></b><br />
<br />
Windows 3 was the first version to see more widespread success and be considered a challenger to Apple’s Macintosh and the Commodore Amiga graphical user interfaces, coming pre-installed on computers from PC-compatible manufacturers including Zenith Data Systems.<br />
<br />
<b><span style="color: #0b5394;">Windows 95</span></b><br />
<br />
As the name implies, Windows 95 arrived in August 1995 and with it brought the first ever Start button and Start menu. Internet Explorer also made its debut on Windows 95.<br />
<br />
<b><span style="color: #0b5394;">Windows 98</span></b><br />
<br />
Released in June 1998, Windows 98 built on Windows 95 and brought with it IE 4, Outlook Express, Windows Address Book, Microsoft Chat and NetShow Player, which was replaced by Windows Media Player 6.2 .<br />
<br />
<b><span style="color: #0b5394;">Windows ME</span></b><br />
<br />
It was the consumer-aimed operating system coupled with Windows 2000 aimed at the enterprise market. It introduced some important concepts to consumers, including more automated system recovery tools.<br />
<br />
<b><span style="color: #0b5394;">Windows 2000</span></b><br />
<br />
Microsoft’s automatic updating played an important role in Windows 2000 and became the first Windows to support hibernation.<br />
<br />
<b><span style="color: #0b5394;">Windows XP</span></b><br />
<br />
Windows XP was the longest running Microsoft operating system, seeing three major updates. Its biggest problem was security: though it had a firewall built in, it was turned off by default.<br />
<br />
<b><span style="color: #0b5394;">Windows 7</span></b><br />
<br />
It was faster, more stable and easier to use, becoming the operating system most users and business would upgrade to from Windows XP.<br />
<br />
<b><span style="color: #0b5394;">Windows 8</span></b><br />
<br />
The new tiled interface saw programme icons and live tiles normally associated with “widgets”. Windows 8 was faster than previous versions of Windows and included support for the new, much faster USB 3.0 devices.<br />
<br />
<b><span style="color: #0b5394;">Windows 10</span></b><br />
<br />
Announced on 30 September 2014, Windows 10 has only been released as a test version for keen users to try. The “technical preview” is very much still a work in progress.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-77927078631240050552020-08-02T01:28:00.003-07:002021-08-23T01:12:20.524-07:00Functions of Operating System<div dir="ltr" style="text-align: left;" trbidi="on">
There are Many Functions those are Performed by the Operating System. But the Main Goal of Operating System is to Provide the Interface between the user and the hardware.<br />
<br />
<b><span style="color: #0b5394;">Device Management</span></b><br />
<br />
OS manages device communication via their respective drivers. Operating System does the following activities for device management. Keeps tracks of all devices. Programs responsible for this task is known as the I/O controller. Decides which process gets the device when and for how much time. Allocates and de-allocates the device in the efficient way.<br />
<br />
<b><span style="color: #0b5394;">File Management</span></b><br />
<br />
A file system is normally organized into directories for easy navigation and usage. These directories may contain files and other directions. Operating System does the following activities for file management. Keeps track of information, location, uses, status etc. The collective facilities are often known as file system. Decides who gets the resources. Allocates the resources.<br />
<br />
<b><span style="color: #0b5394;">Memory Management</span></b><br />
<br />
Memory management refers to management of Primary Memory or Main Memory. Main memory is a large array of words or bytes where each word or byte has its own address. Main memory provides a fast storage that can be access directly by the CPU. So for a program to be executed, it must in the main memory. Operating System does the following activities for memory management. Keeps tracks of primary memory i.e. what part of it are in use by whom, what part are not in use.<br />
<br />
<b><span style="color: #0b5394;">Processor Management</span></b><br />
<br />
In multi-programming environment, OS decides which process gets the processor when and how much time. This function is called process scheduling. Operating System does the following activities for processor management. Keeps tracks of processor and status of process. Program responsible for this task is known as traffic controller. Allocates the processor (CPU) to a process. De-allocates processor when processor is no longer required.<br />
<br />
<b><span style="color: #0b5394;">Types of Operating system</span></b><br />
<br />
There are 4 types of operating system. They are explained below.<br />
<br />
Batch Operating System:-A batch system is one in which jobs are bundled together with the instructions necessary to allow them to be processed without intervention<br />
<br />
<b><span style="color: #0b5394;">Multi-programming Operating System</span></b><br />
<br />
As machines with more and more memory became available, it was possible to extend the idea of multi-programming (or multiprocessing) as used in spooling batch systems to create systems that would load several jobs into memory at once and cycle through them in some order, working on each one for a specified period of time. There are different type of Multi-programming Operating System, some main stream are discussed below.<br />
<ul style="text-align: left;">
<li><b>Multitasking Operating System</b> – A running state of a program is called a process or a task.multitasking allows the computer system to more reliably guarantee each process a regular “slice” of operating time. It also allows the system to rapidly deal with important external events like incoming data, which might require the immediate attention of one or another process. So, multitasking operating system is a type of multi-programming operating system which can perform several process simultaneously.</li>
<li><b>Multi-user Operating System</b> – A multi-user operating system allows for multiple users to use the same computer at the same time and/or different times. Linux,Unix,Windows OS are some example of multitasking operating system.</li>
<li><b>Multiprocessing Operating System</b> – An operating system capable of supporting and utilizing more than one computer processor.Linux,Unix,Windows OS are some example of multitasking operating system</li>
<li><b>Real Time Operating System </b>– It is an OS where there are a number of possibly unrelated external activities needed to be controlled by a single processor system.</li>
<li><b>Network Operating System </b>– A network operating system (NOS) is software that controls a network and its message (e.g. packet) traffic and queues, controls access by multiple users to network resources such as files, and provides for certain administrative functions, including security.</li>
<li><b>Distributed Operating System </b>– Distributed systems are very much like traditional operating systems. First, they act as resource managers for the underlying hardware, allowing multiple users and applications to share resources such as CPUs, memories, peripheral devices, the network, and data of all kinds.</li>
</ul>
<b><span style="color: #38761d;">USER INTERFACE</span></b><br />
<br />
<b><span style="color: #0b5394;">Character user interface</span></b><br />
<br />
CUI is another name for a command line. Sometimes referred to as the command screen or a text interface, the command line is a user interface that is navigated by typing commands prompts, as opposed to using the mouse to perform a command. Unlike a GUI operating system, a command line only uses a keyboard to navigate by entering commands and does not utilize a mouse.<br />
<br />
Because a command line interface requires unique commands, this interface is often more difficult to learn because of the need to memorize different commands. However, a command line operating system can be a very valuable resource and should not be ignored. For example, users who have Microsoft Windows may find trivial tasks such as renaming 100+ files in a folder a very difficult task; however, this is something that can be done in a matter of seconds through a simple command at the command line.<br />
<br />
<b><span style="color: #0b5394;">Graphical User Interface</span></b><br />
<br />
A GUI uses windows, icons, and menus to carry out commands, such as opening, deleting, and moving files. Although many GUI operating systems are through the use of a mouse, the keyboard can also be utilized by using keyboard shortcuts or arrow keys.Unlike a command line operating system or CUI like Unix or MS-DOS, GUI operating systems are much easier to learn and use because commands do not need memorized. Additionally, users do not need to know any programming languages. Because of their ease of use, GUI operating systems have become the dominant operating system today’s end-users.<br />
<br />
<b>A few examples of a GUI operating system </b><br />
<ul style="text-align: left;">
<li>Microsoft Windows</li>
<li>Linux</li>
<li>Chrome OS</li>
</ul>
</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-79032746137697781612020-08-02T00:27:00.003-07:002021-08-23T01:12:20.524-07:00Data Communication and Network<div dir="ltr" style="text-align: left;" trbidi="on">
Data communications refers to the transmission of digital data between two or more computers and a computer network. The physical connection between networked computing devices is established using either cable media or wireless media. The best-known computer network is the Internet.<br />
<br />
The transmission of data is carried out by the propagation and processing of signals. The different types of transmission are,<br />
<br />
<b>Parallel Data Transmission </b>– The sender sends all the bits at once on all lines. Because data lines are equal to the number of bits in a group or data frame. Advantage of Parallel transmission is speed and disadvantage is the cost of wires, as it is equal to the number of bits needs to send parallelly.<br />
<b>Serial Data Transmission </b>– Bits are sent one after another in a queue manner. It is slower than the Parallel Data Transmission.<br />
<b>Synchronous Data Transmission</b> – Data-bits have specific pattern and helps receiver<br />
recognize when the actual data bits start and where it ends<br />
Computer Network and it’s Types<br />
<br />
The different types of Computer Networks are,<br />
<ul style="text-align: left;">
<li>Personal Area Network</li>
<li>Local Area Network</li>
<li>Metropolitan Area Network</li>
<li>Wide Area Network</li>
<li>Storage Area Network</li>
<li>System Area Network</li>
<li>Controller Area Network</li>
</ul>
<b><span style="color: #0b5394;">Personal Area Network (PAN)</span></b><br />
<br />
PAN is the smallest network which is very personal. PAN network has a connectivity range of 10 meters. Bluetooth devices and Infra-Red devices are the common PAN devices. Bluetooth enabled Keyboard or Mouse, TV remote, wireless printers are some examples of PAN network.<br />
<br />
<b><span style="color: #0b5394;">Local Area Network (LAN)</span></b><br />
<br />
LAN is a computer network spanned inside a building and operated under single administrative system. Each computer is connected by cables. LAN provides a useful way of sharing resources between end users. LANs are capable of transmitting data at very fast rates, much faster than data can be transmitted over a telephone line; but the distances are limited. Resources like Printers, File Servers, Scanners and internet is easy sharable among computers.<br />
<br />
<b><span style="color: #0b5394;">Metropolitan Area Network (MAN)</span></b><br />
<br />
A network spanning a physical area larger than a LAN but smaller than a WAN, such as a city. A MAN is typically owned an operated by a single entity such as a government body or large corporation. MANs provide Internet connectivity for LANs in a metropolitan region, and connect them to WANs like the Internet.<br />
<br />
<b><span style="color: #0b5394;">Wide Area Network (WAN)</span></b><br />
<br />
A computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks (LANs). Generally, telecommunication networks are Wide Area Network. These networks provides connectivity to MANs and LANs. Equipped with very high speed backbone, WAN uses very expensive network equipment.They can also be connected through leased lines or satellites. The largest WAN in existence is the Internet.<br />
<br />
<b><span style="color: #0b5394;">Storage Area Network (SAN)</span></b><br />
<br />
A Storage area network is a high-speed network of storage devices that also connects those storage devices with servers. SAN storage devices can include tape libraries, and, more commonly, disk-based devices.<br />
<br />
<b><span style="color: #0b5394;">System Area Network</span></b><br />
<br />
System Area Network links high-performance computers with high-speed connections in a cluster configuration. Also known as Cluster Area Network.<br />
<br />
<b><span style="color: #0b5394;">Controller Area Network</span></b><br />
<br />
Controller Area Network is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other within a vehicle without a host computer.<br />
<br />
<b><span style="color: #0b5394;">Communication</span></b><br />
<br />
Communication is carried out by means of<br />
<br />
<b>Modem </b>– a device that enables a computer to transmit data over telephone lines.<br />
<b>Optical Fiber </b>– permit transmission over longer distances and at higher bandwidths.<br />
<b>Satellites </b>– data can be transferred from one part of the world to any part of the world.<br />
<b>Twisted pair wire </b>– used for telephone lines<br />
<b>Coaxial cable </b>– a type of cable that is used by cable TV and that is common for data communications</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-37883145791271979342020-08-02T00:24:00.001-07:002021-08-23T01:12:20.521-07:00Some Important File Formats<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: #0b5394;">Some Important Video File Formats</span></b><br />
<ul style="text-align: left;">
<li>3GP – Third Generation Partnership Project</li>
<li>AVI- Microsoft Audio Visual Interleaved</li>
<li>DIVX- Digital Video Express Encoded Movie Files</li>
<li>FLV- Flash Video</li>
<li>MKV – Matroska Video File</li>
<li>MPEG- Motion Picture Experts Group file interchange format</li>
<li>MP4- MPEG-4 Video Stream</li>
<li>MTS- AVCHD Video File</li>
<li>VOB- Video Object File</li>
<li>WMV- Windows Media Video</li>
</ul>
<b><span style="color: #0b5394;">Some Important Audio File Formats</span></b><br />
<ul style="text-align: left;">
<li>MIDI- Musical Instrument Digital Interface MIDI-sequention Sound</li>
<li>MP3- MPEG Layer 3 Audio</li>
<li>WMA- Windows Media (Metafile)</li>
</ul>
<b><span style="color: #0b5394;">Some Important Image File Formats</span></b><br />
<ul style="text-align: left;">
<li>BMP- Microsoft Windows BITMAP</li>
<li>GIF- Graphics Interchange Format</li>
<li>JPEG, JPG- Joint Photographic Experts Groupt</li>
<li>PNG- Portable Network Graphics</li>
<li>PSD- Adobe Photoshop Document</li>
<li>TIF- Tagged Image File Format</li>
<li>AI- Adobe Illustrator File</li>
<li>SVG- Scalable Vector Graphics File</li>
<li>VSD- Microsoft Visio Document</li>
</ul>
<b><span style="color: #0b5394;">Some Important Document File Formats</span></b><br />
<ul style="text-align: left;">
<li>DOC- Microsoft Word Binary File Format</li>
<li>DOCX- Microsoft Word Open XML Document</li>
<li>ODT- OpenDocument Text Document</li>
<li>PDF- Portable Document Format</li>
<li>RTF- Rich Text Format</li>
<li>SWF- Shockwave Flash Movie</li>
<li>XLS- Microsoft Excel Spreadsheet</li>
<li>XML- Extensible Markup Language</li>
<li>CSV- Comma Separated Values File</li>
<li>ODS- OpenDocument Spreadsheet</li>
<li>XLSX- Microsoft Excel Open XML Spreadsheet</li>
<li>KEY- Keynote Presentation</li>
<li>PPT- Microsoft PowerPoint</li>
<li>PPTX- Microsoft PowerPoint 2007 XML</li>
<li>PPS- PowerPoint Slide Show</li>
</ul>
<b><span style="color: #0b5394;">MISC</span></b><br />
<ul style="text-align: left;">
<li>DAT- Data File</li>
<li>EXE- Executable file</li>
<li>TTF- TrueType Font</li>
<li>VCF- vCard File</li>
</ul>
</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-27920616436964517982020-08-02T00:16:00.002-07:002021-08-23T01:12:20.520-07:00Optical Discs<div dir="ltr" style="text-align: left;" trbidi="on">
Optical Discs are storage devices, in which the data is stored in the form of Binary values. The writing is carried out either optically or mechanically and reading is done using Laser Beams. Based on the technology used to manufacture and read write process, there are different types of Discs like CD, DVD, Blu-ray etc. Optical discs store much more data than Magnetic Storage Devices. Optical discs were invented by David Paul Gregg in 1958 for video recording. Optical discs are mainly made of Plastic and Poly Carbonate material.<br />
<br />
The binary data is written into the Disc in the form of PITs (Binary Value ‘0’) and LANDs (Binary Value ‘1’). The reading is done from outer side to inner side and the writing is done from inner side to outer side. Mainly the frequency of PITs and LANDs decides the storage space in the disc. If we are using high frequency lights like Blu-ray Laesr, we can read and write more binary numbers from and into a single disc.<br />
<br />
Compact Disc (CD)<br />
<br />
These kind of discs are mainly used for storing music and Software packages. The typical storage is 760 MB. There are different versions available for these kinds of discs. They are CD-R (ROM), CD-RW (Re-Writable). The typical wavelength of the laser beam used to read the data from the CD is 780nm.<br />
<br />
<b><span style="color: #0b5394;">Digital Versatile Disc (DVD)</span></b><br />
<br />
These kind of discs are mainly used for storing movies and Games. The typical storage is 4.7 GB. In DVD also there are different versions available ike DVD-R, DVD-RW etc. The typical wavelength of the laser beam used to read the data from the DVD is 650 nm.<br />
<br />
<b><span style="color: #0b5394;">Blu-Ray Disc (BD)</span></b><br />
<br />
These are the latest improvement in Optical Discs. They are mainly used to store High Definition Movies, Games with High Graphics or to store more than one movies in a single disc. Watching contents from these kind of discs will provide a theatrical experience to the audience. The typical storage space in a Blu-Ray disc is about 25GB. The typical wavelength of the laser beam used to read the data from a Blu-ray disc is 405 nm.<br />
<br />
The main <b>disadvantages </b>of Optical disc is that they are made of thin plastic material which is not protected with a case. Hence it is prone to Mechanical deformation, dust, scratches etc.<br />
<br />
However, Optical discs are light weight with more storage density and immune to Electro Magnetic interference. The storage density can be improved using multi layered recording in which more than one layer is used to record the data.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-440794424474845952020-08-02T00:14:00.004-07:002021-08-23T01:12:20.517-07:00Computer Virus<div dir="ltr" style="text-align: left;" trbidi="on">
A computer virus is a coded program intended to cause destruction to data or system operations knowingly or unknowingly to the user. They carry out their functions by replicating or copying themselves to other vulnerable areas. The functions of the virus depend on the program code. Examples of their function are stealing of personal data, computer memory loss, replicating through spamming, etc.,<br />
<br />
<b><span style="color: #0b5394;">Boot virus:</span></b><br />
<b><br /></b>
<b>Boot virus </b>(Trojans) affect the disk operating system, thereby corrupting the booting files in spite of the operating system used. The main distinction is that they don’t replicate but spread on opening an email attachment specifically.<br />
<br />
<b><span style="color: #0b5394;">Macro virus:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
<b>Macro virus </b>(Worms) are intended to affect data files specifically by finding vulnerabilities in word or excel documents. They infect by replicating to other systems in the network. They don’t require a host file to replicate themselves.<br />
<br />
<b><span style="color: #0b5394;">Hacking and computer fraud</span></b><br />
<br />
Hacking is an act performed to gain personal data or sensitive information through vulnerabilities in your computer network or program. It is unethical to perform hacking as it neglects privacy issues.<br />
<br />
Computer fraud is a piracy performed with the help of computer techniques to procure any data which leads to another’s monetary gain. Computer fraud faces tough challenges for preventing at this era.<br />
<br />
<b><span style="color: #0b5394;">Data security</span></b><br />
<br />
Data security is the prevention of one’s private or corporate data files falling into personnel who exploit the privacy issues of the data. The data protection act of the United Kingdom was unveiled for data security. This ensured that data security breaching is considered unlawful.<br />
<br />
<b><span style="color: #0b5394;">Prevention measures:</span></b><br />
<br />
The prevention measures for viruses, hacking, computer fraud and data security breaching are as follows<br />
<br />
<ul style="text-align: left;">
<li>Ensure your computer is updated with latest software updates and OS system updates to seal off the vulnerabilities.</li>
<li>Ensure you have an antivirus program, anti-malware program and firewall system with latest updates.</li>
<li>Ensure you don’t open any un-authorised mails containing documents.</li>
<li>Ensure you don’t download software programs developed by individuals.</li>
<li>Ensure you don’t provide your bank details on unauthorised sites.</li>
<li>Ensure you don’t navigate into a hacked site as you are more prone to data breach.</li>
<li>Ensure you change your every online password periodically to ensure safety.</li>
</ul>
</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-3465972179935517842020-08-02T00:12:00.003-07:002021-08-23T01:12:20.517-07:00Network Topology<div dir="ltr" style="text-align: left;" trbidi="on">
Network topology is a usually schematic description of the arrangement of a network, including its nodes and connecting lines.<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUHi7WXMvvCnHlYU-J5b0Yy8shhmCudvcevv_dQnFAKnEFDvkwZY76iQhiDwPiH762G4U4DpL7lGVrFKs5LOayxYgCKkedXlKAazQQzS7piOGVBvS_2LoLl4SdTEQG1pumbGmmKSRAOBk/s1600/topology.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="429" data-original-width="346" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUHi7WXMvvCnHlYU-J5b0Yy8shhmCudvcevv_dQnFAKnEFDvkwZY76iQhiDwPiH762G4U4DpL7lGVrFKs5LOayxYgCKkedXlKAazQQzS7piOGVBvS_2LoLl4SdTEQG1pumbGmmKSRAOBk/s320/topology.gif" width="258" /></a></div>
<br />
<b><span style="color: #0b5394;">Bus network topology:</span></b><br />
<br />
In the <b>bus network topology</b>, every workstation is connected to a main cable called the bus. Therefore, in effect, each workstation is directly connected to every other workstation in the network. It is one of the simple forms of networking where a failure of a device does not affect the others. But failure of the shared communication line make all other devices fail.<br />
<br />
<b><span style="color: #0b5394;">Star network topology:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
In the <b>star network topology</b>, there is a central computer or server to which all the workstations are directly connected. Every workstation is indirectly connected to every other through the central computer. It is easy to install but the dependency on the central computer is high.<br />
<br />
<b><span style="color: #0b5394;">Ring network topology:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
In the <b>ring network topology</b>, the workstations are connected in a closed loop configuration. Adjacent pairs of workstations are directly connected. Other pairs of workstations are indirectly connected, the data passing through one or more intermediate nodes. If one fails, the whole LAN fails.<br />
<br />
<b><span style="color: #0b5394;">Token Ring protocol:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
If a <b>Token Ring protocol</b> is used in a star or ring topology, the signal travels in only one direction, carried by a so-called token from node to node.<br />
<br />
<b><span style="color: #0b5394;">Mesh network topology:</span></b><br />
<br />
The <b>mesh network topology</b> employs either of two schemes, called full mesh and partial mesh. In the full mesh topology, each workstation is connected directly to each of the others. In the partial mesh topology, some workstations are connected to all the others, and some are connected only to those other nodes with which they exchange the most data.<br />
<br />
<b><span style="color: #0b5394;">Tree network topology:</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
The <b>tree network topology</b> uses two or more star networks connected together. The central computers of the star networks are connected to a main bus. Thus, a tree network is a bus network of star networks. Also known as Hierarchical Topology is the most common form of network topology in use presently.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-11062305870022553262020-08-02T00:06:00.003-07:002021-08-23T01:12:20.518-07:00Network Devices<div dir="ltr" style="text-align: left;" trbidi="on">
Computer Network is an interconnection of Computers and other devices which are capable of communicating to the Internet world. The Network can be Wired Network or Wireless Network. The main Component of Computer Network is a Computer, also known as Work Station. However there are some other devices which makes this communication possible.<br />
<br />
<b><span style="color: #0b5394;">Modem</span></b><br />
<br />
MODEM refers to Modulator-Demodulator. It is a device which can convert one form of signal into another form.<br />
<br />
<b>1. Telephone Modem/Dialup Modem</b><br />
<br />
The earlier days, Telephone lines were used to connect Computers to the Internet. We know that computer are digital devices and Telephone lines on those days were Analog Type. Now we need something to convert the Digital Data into Analog form and vice verse. The Device used for this purpose is known as Modem. The circuitry for the same is incorporated in the Network Card of Computers and Laptops.<br />
<br />
<b>2. GSM Modem/Mobile Broadband Modem</b><br />
<br />
This is an electronic wireless device, which can be connected to a Computer or a Laptop. This device is also known as a Dongle. It has a Sim Card slot through which it can communicate to the internet via the Mobile Service Provider. It can be considered as a dedicated Mobile Phone for Internet access connected to a Computer.<br />
<br />
<b>3. Wireless Modem/Wi-Fi Modem</b><br />
<br />
This is another electronic wireless device, which can be connected to a Router, or a Broadband line to convert the signals into Wireless Signals (Wi-Fi) in Micro Wave Frequency. The signals arriving at the Router or Broadband line are mainly in Radio Frequency Range. The main purpose of this device is to convert this radio frequency signals into a smaller frequency, which is known as<br />
<br />
<b><span style="color: #0b5394;">Hub</span></b><br />
<br />
Hub is also known as a repeater which work in the Physical Layer of the OSI Model. It has many input/output ports. It is mainly used for Network sharing. Consider you have an Wired Broadband BSNL internet connection to your room. You want to share the internet with your room mates. A Hub is useful in this situation. We will connect the external internet connection to one of the port. This internet connection will be shared now and available to all the other ports in the Hub. Your room mates can connect Ethernet cable from the other ports of the Hub to their Computer. RJ45 is the connector used to connect the Ethernet cable to the Hub.<br />
<br />
<b><span style="color: #0b5394;">Switch</span></b><br />
<br />
Switch is also known as MAC bridge, which work in the Datalink Layer of the OSI Model. Like Hub, Switch also has lot of input/output ports. The main difference between Hub and Switch is that, Hub will simply broadcast the messages arriving at the input. However, Switch has the capability to selectively route the message to specific ports. The routing is done using the MAC address of each devices connected to it.<br />
<br />
<b><span style="color: #0b5394;">Router</span></b><br />
<br />
Router is a traffic directing device which works in the Network Layer of the OSI Model. When a packet data arrives at the input port of the Router, it will forward the data to the next destination of the data based on the information available in the Routing Table. The traffic directing is carried in Router using IP Address of the Destination. The main purpose of Router is to connect multiple networks and direct the packets to same network or another network.<br />
<br />
<b><span style="color: #0b5394;">Gateway</span></b><br />
<br />
Gateway is a Network device which can operate in any layer of the OSI Model. It is device used to connect different networks, operating with different protocols. Gateway is a complex device than Router.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-60373808820711086042020-08-02T00:04:00.002-07:002021-08-23T01:12:20.523-07:00Internet – an Overview<div dir="ltr" style="text-align: left;" trbidi="on">
The Internet is a collection of computers connected by network cables or through satellite links. The internet is a worldwide computer network that interconnects millions of computing devices throughout the world. Most of these computing devices are traditional desktop PCs, Unix-based workstations, and so called servers that store and transmit information such as Web (WWW) pages and e-mail.<br />
<br />
<b>The TCP (Transmission Control Protocol) and IP (Internet Protocol) </b>are two of the most<br />
important protocols in the Internet. The Internet ’s principal protocols are collectively known as TCP/IP. End systems are connected together by communication links.<br />
<br />
The Internet allows distributed applications running on its end systems to exchange data with each other. These applications include remote login, file transfer, electronic mail, audio and video streaming, real-time audio and video conferencing, distributed games, the World Wide Web etc.<br />
<br />
<b><span style="color: #0b5394;">World Wide Web</span></b><br />
<br />
In 1989, Tim Berners-Lee at CERN proposed a protocol to exchange documents with colleagues around the world. The idea was that users could search for and retrieve any document on the Internet. The form of the documents was hypertext. This meant any given document could have links to other documents on the Internet. In a strict sense, the World Wide Web was this interconnected system of documents.<br />
<br />
<b><span style="color: #0b5394;">Web Browsers</span></b><br />
<br />
A browser is a special software program also known as a client that requests servers for a specific web document and renders it on the computer terminal for the user. One of the oldest browsers is Lynx. This is a text only browser. The earliest graphical browser was Mosaic developed at the National Center for Supercomputer Applications (NCSA) at the University of Illinois. There are other browsers available – Mozilla, Opera, Chrome, IE, and Safari. The browsers communicate with the servers using the standard Hypertext Transfer Protocol (HTTP).<br />
<br />
<b><span style="color: #0b5394;">Web Servers</span></b><br />
<br />
A web server is a software program that provides documents to browsers. Apache is the most widely used web server with 68% of the market share. Second is Microsoft’s Internet Information Server (IIS) with about 21% of the market share. And the remainder is spread over a large number of other servers. A web browser initiates a request with a server by sending it the URL of a document. The server searches, retrieves and sends the document.<br />
<br />
<b><span style="color: #0b5394;">URL</span></b><br />
<br />
Uniform (or universal) resource locators are used to identify documents or resources on the Internet. A URL has two main components: Protocol identifier and Resource name. For the URL https://affairscloud.com, the Protocol Identifier is http and the Resource Name is affairscloud.com.<br />
<br />
<b><span style="color: #0b5394;">HTTP</span></b><br />
<br />
HTTP stands for Hypertext Transfer Protocol. It is an application protocol for distributed, collaborative, hypermedia information systems. it is the foundation of data communication for the World Wide Web. Hypertext is structured text that uses logical links (hyperlinks) between nodes containing text.<br />
<br />
<b><span style="color: #0b5394;">DNS</span></b><br />
<br />
DNS stands for Domain Name Servers. They are the Internet’s equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses. This is necessary because, although domain names are easy for people to remember, computers or machines, access websites based on IP addresses.<br />
<br />
<b><span style="color: #0b5394;">E-Commerce</span></b><br />
<br />
E-Commerce refers to Electronic Commerce. It is nothing but trading of products or services using internet. The companies such as Flipkart, Snapdeal, Alibaba are all E-Commerce companies.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-82809183513127020112020-08-02T00:00:00.001-07:002021-08-23T01:12:20.525-07:00Data and Procedure<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: #0b5394;">Data</span></b><br />
<br />
Computer data is information processed or stored by a computer. This information may be in the form of text documents, images, audio clips, software programs, or other types of data. Computer data may be processed by the computer’s CPU and is stored infiles and folders on the computer’s hard disk.<br />
<br />
At its most rudimentary level, computer data is a bunch of ones and zeros, known as binary data. Because all computer data is in binary format, it can be created, processed, saved, and stored digitally. This allows data to be transferred from one computer to another using a network connection or various media devices. It also does not deteriorate over time or lose quality after being used multiple times.<br />
<br />
<b><span style="color: #0b5394;">Procedure</span></b><br />
<br />
In computer programming, a procedure is an independent code module that fulfills some existing task and is referenced within a larger body of source code. This kind of code item can also be called a function or a sub-routine. The fundamental role of a procedure is to offer a single point of reference for some small goal or task that the developer or programmer can trigger by invoking the procedure itself.<br />
<br />
The code for a procedure will be stored within identifiers for that procedure to mark it as separate from the larger code. In some cases, procedures are part of external libraries that can be called by developers from those library files. In other cases, they are written in customized ways within the program. The procedure is a basic building block for what’s called object oriented programming, which has brought a more powerful set of tools to today’s developer community.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-47035016963218072202020-08-01T23:58:00.003-07:002021-08-23T01:12:20.522-07:00Programming Languages of Computer<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: #0b5394;">What is programming language?</span></b><br />
<br />
Coded language used by programmers to write instructions that a computer can understand to do what the programmer or the computer user wants.<br />
<br />
<b><span style="color: #0b5394;">High level language</span></b><br />
<br />
High level languages are designed to be used by the the programmer. Their programming style and context is easier to learn and implement, and the entire code generally focuses on the specific program to be created.<br />
<br />
High-level language doesn’t require addressing hardware constraints to a greater extent when developing a program. However, every single program written in a high level language must be interpreted into machine language before being executed by the computer. The main advantage of high-level languages over low-level languages is that they are easier to read, write, and maintain.<br />
<br />
BASIC, C/C++ and Java are popular examples of high-level languages.<br />
<br />
<b>Advantage of high-level language:</b><br />
<ul style="text-align: left;">
<li>Easier to learn and understand.</li>
<li>Less time to write program.</li>
<li>Easier to maintain.</li>
</ul>
<b>Disadvantage of high-level language:</b><br />
<ul style="text-align: left;">
<li>It takes more time to execute the program.</li>
<li>Difficult in debugging if proper code is not available.</li>
<li>Inability to perform all operations because cannot manipulate bits and registers.</li>
</ul>
<b><span style="color: #0b5394;">Machine Level Language</span></b><br />
<br />
Machine level language is a machine language that a computer can understand directly without any difficulty. It is made up of series of 1’s and 0’s. The order of the bits serves as a code specifying what the computer should do.<br />
<br />
<b>Advantages:</b><br />
<ul style="text-align: left;">
<li>Computer directly understands the code written in this language therefore execution speed is fast and use of primary memory.</li>
</ul>
<b>Disadvantages:</b><br />
<ul style="text-align: left;">
<li>Difficult to learn and program.</li>
<li>The program becomes very lengthy and difficult to locate the errors.</li>
<li>difficult to debug.</li>
<li>Programs written in machine language in one machine cannot be easily transferred to other machines.</li>
</ul>
<b><span style="color: #0b5394;">Assembly Language </span></b><br />
<br />
Assembly language is the language that permits the use of mnemonics for each instructing that the machine can do. The program written in assembly language must be transmitted to machine understandable form, which is done by assembler because computer cannot understand mnemonics codes(alphabetic codes) such as ADD for addition, SUB for subtraction etc. The program written by the programmer in assembly language is called a source program. The program, which is obtained after being converted into machine language, is called object program. It is also machine-oriented language ie. Designed for specific make and model of a computer.<br />
<br />
<b>Advantages:</b><br />
<ul style="text-align: left;">
<li>Simple to understand and use when compared to machine level language.</li>
<li>Less time is required to write the program</li>
<li>Program debugging is easier .</li>
</ul>
<b>Disadvantages:</b><br />
<ul style="text-align: left;">
<li>It is machine dependent i.e. each design of machine has a different assembly language.</li>
<li>Assembly level language is too difficult to understand than the high level language.</li>
<li>Coding in this language is time-consuming.</li>
</ul>
</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-70158438386696972502020-08-01T23:53:00.003-07:002021-08-23T01:12:20.523-07:00All about Programming Languages<div dir="ltr" style="text-align: left;" trbidi="on">
Language is a means by which we communicate with others. Each language has its own specialties. For example English Language has 26 alphabets, Uppercase and Small case, words with different meaning and pronunciation, sentences, grammar etc.<br />
<br />
<b><span style="color: #0b5394;">What is Programming Language?</span></b><br />
<br />
It is a Language we used to communicate with Computers. There are lot of programming languages with its own purposes and syntax.<br />
<br />
<b><span style="color: #0b5394;">Why we need Programming Languages?</span></b><br />
<br />
It is because Computer does not have a brain to take its own decisions and act accordingly. It does not have the capability to respond to the directions and instructions given by the human beings in their language. It needs to be programmed before use. We need a different Language to Communicate with the Computers. These are known as Computer Programming Languages. Program is a set of instructions given to the Computer so that it can handle different situations and scenarios.<br />
<br />
<b><span style="color: #0b5394;">How a Computer Program works?</span></b><br />
<br />
Computer is having a Microprocessor made of millions of transistors. It can handle basic logical and arithmetic operations and accept different inputs and produce different outputs. A Microprocessor is having all resources for handling data, performing logical and arithmetic operations on the data, produce different output based on the operations in it and to control different input output peripherals connected to it. Now programs are instructions which describe the sequence and use of different resources in the Microprocessor to carry out certain tasks.<br />
<br />
The Language used to program a Microprocessor is called Machine Level language, which is the very basic Computer Programing Language. It is also known as Binary Level Language (A Language composed of only 1s and 0s). However it is a tedious task to program a computer using Machine Level Language as it lengthy, time consuming and complex. However we should remember that the old computers were programmed using this Language.<br />
<br />
To make Programming easier, an Assembly Level Language is introduced. These are certain English words used to Program and process data in a Micro Processor. The Assembly Level Languages are converted into Hex Code (A number system with base 16) using a compiler. An assembler is a program which converts the Machine Code into Hex Code.<br />
<br />
Then comes the Middle Level Language. The main purpose of these language is to make programing easier and less complex. These programs are easily understandable by human being. However the Microprocessor in Computers can understand only Machine Level Languages. Now who will translate the Middle level Languages to Machine Level Languages? The Software used to convert the middle level language into Machine Level language is called Compiler. Interpreter is another Software which is used to Execute the Computer Program directly without converting it into Machine Level Language. Debugger is a Software used to check the syntactical mistake (grammar mistakes in Computer Programming) in Middle Level Language before converting it into Machine Level Language.<br />
<br />
There are different High Level languages which makes the programming more easier as its syntax and usage of words are almost similar to common English Language. However the pain of conversion of this High Level Language to Machine Level Language will be handled by the Compiler.<br />
<br />
<b>Some Low Level Languages: </b>PL/S, BLISS, BCPL, ALGOL, C<br />
<br />
<b>Some Middle Level Languages: </b>C#, C++, Java,<br />
<br />
<b>Some High Level Languges:</b> Python, Ruby, and CommonLisp, SQL<br />
<br />
<b>Some Web Designing Languages: </b>PHP, Ruby<br />
<br />
<b>Some Hardware Design Languages: </b>VHDL, Verilog (This Program is exclusively used to design Integrated Circuits(IC Chips))</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-24806498026036216262020-08-01T23:51:00.003-07:002021-08-23T01:12:20.519-07:00Uses of Computer<div dir="ltr" style="text-align: left;" trbidi="on">
The use of Computer has spread around all fields offering the necessity to know about the computer operations widely. It has invaded every field from the ground to the space. Some of the places where computer has shown its importance are<br />
<br />
<b><span style="color: #0b5394;">Household:</span></b><br />
<br />
<ul style="text-align: left;">
<li>Entertainment</li>
<li>Social media & chatting</li>
<li>E-learning & News reading</li>
<li>Home budgeting & Ordering of materials</li>
<li>House hold security & automation</li>
</ul>
<br />
<b><span style="color: #0b5394;">Business:</span></b><br />
<div style="text-align: left;">
</div>
<ul style="text-align: left;">
<li>Marketing</li>
<li>E-filling of taxes & E-billing</li>
<li>Stock Exchange</li>
<li>ERP (Enterprise Resource Planner)</li>
<li>E-commerce</li>
<li>Business security monitoring</li>
<li>Teleconferencing</li>
<li>IT support (Information and Technology)</li>
<li>BPO (Business Process Out-sourcing) & KPO (Knowledge Process out-sourcing).</li>
</ul>
<br />
<b><span style="color: #0b5394;">Medical Field:</span></b><br />
<br />
<ul style="text-align: left;">
<li>Hospital management</li>
<li>Patient monitoring</li>
<li>Life support system</li>
<li>Tele-medicine</li>
<li>Diagnostics</li>
</ul>
<br />
<b><span style="color: #0b5394;">Education & Research:</span></b><br />
<br />
<ul style="text-align: left;">
<li>E-learning & distance learning programs</li>
<li>Computer aided learning</li>
<li>Simulation software's for research</li>
<li>Online or computer based tests</li>
<li>Designing and modelling software</li>
<li>Circulation and reference of study material</li>
</ul>
<br />
<b><span style="color: #0b5394;">Banking:</span></b><br />
<br />
<ul style="text-align: left;">
<li>Internet banking & Mobile banking</li>
<li>Clearing of money at money clearance branch</li>
<li>Accounting of money</li>
<li>NEFT – National Electronic Fund Transfer & RTGS – Real Time Gross Settlement</li>
<li>Record maintenance and risk free backup maintenance.</li>
</ul>
<br />
<b><span style="color: #0b5394;">Space field:</span></b><br />
<br />
<ul style="text-align: left;">
<li>Simulation studies – Tsunami, Cyclone, etc.,</li>
<li>Monitoring of weather through forecast</li>
<li>Satellite controlling.</li>
</ul>
<br />
<b><span style="color: #0b5394;">Geology:</span></b><br />
<br />
<ul style="text-align: left;">
<li>Mineral deposit identification</li>
<li>satellite images.</li>
</ul>
<br />
<b><span style="color: #0b5394;">Defence:</span></b><br />
<br />
<ul style="text-align: left;">
<li>Movement of troops monitoring</li>
<li>Guided targets</li>
<li>GPS (Global Positioning System)</li>
<li>Secure backup files relating to defence</li>
</ul>
<br />
<b><span style="color: #0b5394;">Communication:</span></b><br />
<br />
<ul style="text-align: left;">
<li>Mobile phones</li>
<li>Video chats</li>
<li>Mails</li>
<li>Instant messaging</li>
<li>Backup service of messages</li>
</ul>
</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-2085479911413271002020-08-01T23:47:00.001-07:002021-08-23T01:12:20.517-07:00Computer Classification<div dir="ltr" style="text-align: left;" trbidi="on">
According to size, computer classification are of 4 types namely<br />
<ul style="text-align: left;">
<li>Mainframe computers</li>
<li>Mini computers</li>
<li>Micro computers</li>
<li>Super computers</li>
</ul>
<b><span style="color: #0b5394;">Mainframe computers</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
Mainframe computers occupy large space, sensitive to parameters like temperature, humidity, etc., They have large storage capacity, many accessories or peripherals and performs many tasks. It is not user-friendly, can be used only by qualified or trained professionals. It is used to service multiple users with numerous software. They are used by large corporations, governments, banks, etc.,<br />
<br />
<b><span style="color: #0b5394;">Mini computers</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
Mini computers posses less memory and storage than mainframe computers. They are used for data processing, while they are sensitive to parameters like temperature, humidity, etc., It posses less peripherals and limited software than the mainframe computers.<br />
<br />
<b><span style="color: #0b5394;">Micro computers</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
Micro computers are also known as personal computers. They are cheap, affordable, user-friendly and easily access-able. It is widely used in companies, offices, household, schools, colleges, etc., It posses less accessories like keyboard, mouse, CPU, monitor, etc.,<br />
<br />
<b><span style="color: #0b5394;">Super computers</span></b><br />
Super computers are used for complex mathematical operations. They are used for weather forecasting, nuclear simulations, scientific computations, fluid dynamics, cyclone predication, etc., They are used by research institutions, space centers, weather forecast stations, nuclear power stations, etc.,<br />
<br />
According to functions, computer can be classed into 4 types namely<br />
<ul style="text-align: left;">
<li>Servers</li>
<li>Workstations</li>
<li>Information appliances</li>
<li>Embedded computers</li>
</ul>
<b><span style="color: #0b5394;">Servers</span></b><br />
<br />
Servers are the kind of computer used to provide services. It depends on the service like database, file, web, etc.,<br />
<br />
<b><span style="color: #0b5394;">Workstations</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
Workstations are kind of computers intended to single user but can use multi-user operating system.<br />
<br />
<b><span style="color: #0b5394;">Information appliances</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
Information appliances are the portable or handy devices designed to perform simple operations like calculations, games, etc., They have limited memory and limited operations capabilities and software.<br />
<b><br /></b>
<b>Example –</b> Mobile phones, Tablets, etc.,<br />
<br />
<b><span style="color: #0b5394;">Embedded Computers</span></b><br />
<b><span style="color: #0b5394;"><br /></span></b>
Embedded computers are used in another machines to serve limited requirements. It executes program in the non-volatile memory to operate an intended machine or electronic device. They cannot be rebooted unlike normal computers, required to operate continuously. Embedded computers are used widely in day-to-day life. Example – Washing machine, DVD player, etc.,</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-90345053552876757842020-08-01T23:42:00.006-07:002021-08-23T01:12:20.526-07:00Number Systems in a Computer<div dir="ltr" style="text-align: left;" trbidi="on">
A set of values used to represent different quantities is known as Number System. For example, a number system can be used to represent the number of students in a class or number of viewers watching a certain TV program etc. The digital computer represents all kinds of data and information in binary numbers. It includes audio, graphics, video, text and numbers. The total number of digits used in a number system is called its base or radix. The base is written after the number as subscript.<br />
<br />
Some important number systems are as follows.<br />
<ul style="text-align: left;">
<li>Decimal number system</li>
<li>Binary number system</li>
<li>Octal number system</li>
<li>Hexadecimal number system</li>
</ul>
<b><span style="color: #0b5394;">Decimal number System</span></b><br />
<br />
The Decimal Number System consists of ten digits from 0 to 9. These digits can be used to represent any numeric value. The base of decimal number system is 10. It is the most widely used number system. The value represented by individual digit depends on weight and position of the digit.<br />
<br />
<b><span style="color: #0b5394;">Binary Number System</span></b><br />
<br />
Digital computer represents all kinds of data and information in the binary system. Binary Number System consists of two digits 0 and 1. Its base is 2. Each digit or bit in binary number system can be 0 or 1. A combination of binary numbers may be used to represent different quantities like 1001. The positional value of each digit in binary number is twice the place value or face value of the digit of its right side. The weight of each position is a power of 2.<br />
<br />
<b><span style="color: #0b5394;">Octal Number System</span></b><br />
<br />
Octal Number System consists of eight digits from 0 to 7. The base of octal system is 8. Each digit position in this system represents a power of 8. Any digit in this system is always less than 8. Octal number system is used as a shorthand representation of long binary numbers. The number 6418 is not valid in this number system as 8 is not a valid digit.<br />
<br />
<b><span style="color: #0b5394;">Hexadecimal Number System</span></b><br />
<br />
The Hexadecimal Number System consists of 16 digits from 0 to 9 and A to F. The alphabets A to F represent decimal numbers from 10 to 15. The base of this number system is 16. Each digit position in hexadecimal system represents a power of 16. The number 76416 is valid hexadecimal number. It is different from 76410 which is seven hundred and sixty four. This number system provides shortcut method to represent long binary numbers.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-26168977577136721492020-08-01T23:41:00.000-07:002021-08-23T01:12:20.520-07:00Program Compiler and Program Interpreter<div dir="ltr" style="text-align: left;" trbidi="on">
<b><span style="color: #0b5394;">Program Compilation</span></b><br />
<br />
When programmers create software programs, they first write the program in source code, which is written in a specific programming language, such as C or Java. These source code files are saved in a text-based, human-readable format, which can be opened and edited by programmers. However, the source code cannot be run directly by the computer. In order for the code to be recognized by the computer’s CPU, it must be converted from source code (a high-level language) into machine code (a low-level language). This process is referred to as compiling the code.<br />
<br />
Most software development programs include a compiler, which translates source code files into machine code or object code. Since this code can be executed directly by the computer’s processor, the resulting application is often referred to as an executable file. Windows executable files have a .EXE file extension, which is often hidden.<br />
<br />
<b><span style="color: #0b5394;">Program interpreter</span></b><br />
<br />
An interpreter is a program that reads and executes code. This includes source code, pre-compiled code, and scripts. Common interpreters include Perl, Python, and Ruby interpreters, which execute Perl, Python, and Ruby code respectively.<br />
<br />
Interpreters and compilers are similar, since they both recognize and process source code. However, a compiler does not execute the code like and interpreter does. Instead, a compiler simply converts the source code into machine code, which can be run directly by the operating system as an executable program. Interpreters bypass the compilation process and execute the code directly.<br />
<br />
Since interpreters read and execute code in a single step, they are useful for running scripts and other small programs. Therefore, interpreters are commonly installed on Web servers, which allows developers to run executable scripts within their webpages. These scripts can be easily edited and saved without the need to recompile the code. While interpreters offer several advantages for running small programs, interpreted languages also have some limitations.<br />
<br />
The most notable is the fact that interpreted code requires and interpreter to run. Therefore, without an interpreter, the source code serves as a plain text file rather than an executable program. Additionally, programs written for an interpreter may not be able to use built-in system functions or access hardware resources like compiled programs can. Therefore, most software applications are compiled rather than interpreted.</div>
Senthamilselvanhttp://www.blogger.com/profile/04498050566805119459noreply@blogger.com0tag:blogger.com,1999:blog-1527699436958062899.post-90638926841435131042020-08-01T23:39:00.002-07:002021-08-23T01:12:20.526-07:00Storage Devices or Memory Units of a Computer<div dir="ltr" style="text-align: left;" trbidi="on">
torage Devices is the most essential elements in a computer system. The internal storage holds the data while processing.<br />
<br />
When saving anything on a computer, it may ask you for a storage location, which is the area in which you would like to save the information. By default, most information is saved to your computer hard drive.<br />
<br />
Computer Memory is classified into two types.<br />
<ul style="text-align: left;">
<li>Primary Memory</li>
<li>Secondary Memory</li>
</ul>
<b><span style="color: #0b5394;">Primary Memory</span></b><br />
<br />
Primary Memory, also known as main storage, is the area in a computer in which data is stored for quick access by the computer’s processor. It is a computer system’s volatile storage mechanism. This includes several types of memory, such as the processor cache and system ROM. However, in most cases, primary memory refers to system RAM.<br />
<br />
Primary memory is considered faster than secondary memory.<br />
<br />
<b><span style="color: #0b5394;">RAM – Random Access Memory</span></b><br />
<br />
RAM, or random access memory, consists of one or more memory modules that temporarily store data while a computer is running. RAM is Volatile Memory, meaning it is erased when the power is turned off. Therefore, each time you start up your computer, the operating system must be loaded from secondary memory (such as a hard drive) into the primary memory, or RAM. Similarly, whenever you launch an application on your computer, it is loaded into RAM. The two main types of RAM are,<br />
<ul style="text-align: left;">
<li>SRAM – Static RAM</li>
<li>DRAM – Dynamic RAM</li>
</ul>
<b><span style="color: #0b5394;">ROM – Read Only Memory</span></b><br />
<br />
ROM is memory containing hardwired instructions that the computer uses when it boots up, before the system software loads. ROM stores the program required to initially boot the computer. It only allows reading. The data stored on ROM cannot be changed. ROM is Non-Volatile Memory. It can keep the contents without even the power source. The types of ROM include,<br />
<ul style="text-align: left;">
<li>PROM – Programmable ROM</li>
<li>EPROM – Erasable Programmable ROM</li>
<li>EEPROM – Electrically Erasable Programmable ROM</li>
</ul>
<b><span style="color: #0b5394;">Cache Memory</span></b><br />
<br />
Cache memory is a type of memory used to hold frequently used data. Cache memory is relatively small but very fast. Most web browsers use a cache to load regularly viewed web pages fast. The most important type of cache memory is the CPU cache. Once the data is stored in cache, it can be used by accessing the cached copy rather than recomputing the original data.<br />
<br />
<b><span style="color: #0b5394;">Secondary Memory</span></b><br />
<br />
Secondary memory or secondary storage or Auxillary memory is the slowest and cheapest form of memory. It cannot be processed directly by the CPU. It must first be copied into primary storage (also known as RAM). Secondary memory devices include,<br />
<ul style="text-align: left;">
<li>Magnetic disks like hard drives and floppy disks</li>
<li>Optical disks such as CDs and CDROMs</li>
<li>Magnetic tapes</li>
</ul>
<b><span style="color: #0b5394;">Floppy Disks</span></b><br />
<br />
A floppy disk is a secondary storage device. It is a circular piece of plastic material coated with particles, which are magnetized. This thin plastic sheet is protected from outside by a plastic cover to prevent the sensitive data stored on them. The commonly used floppy disks are of 3.5 ” diameter. Floppies are used to store data and transfer them from one computer to another.<br />
<br />
<b><span style="color: #0b5394;">Hard Drives</span></b><br />
<br />
A hard disk is fixed inside the cabinet of CPU (Central Processing Unit). It is made up of many rigid metal platters coated to store data magnetically. The normal speed of hard disks is 3600 revolutions per second. The read/write head of the hard disks moves across its surface. The storage capacity of the hard disks is many times more than the floppy disks.<br />
<br />
<b><span style="color: #0b5394;">CD-ROM</span></b><br />
<br />
CD-ROM stands for Compact Disk – Read Only Memory can store up to 600 to 750 MB of data in it. Once the data is stored into the CD ROM it cannot be erased. In case of Re-writable CDs, the data can be erased and it can be re-used.<br />
<br />
DVD – Digital Versatile Disk can store upto 4.75 GB of data.<br />
<br />
<b><span style="color: #0b5394;">Pen Drive</span></b><br />
<br />
Pen Drive is a small storage device that can be connected to a computer via standard USB (Universal Serial Bus). It is usually removable, re-writable and easy to carry. It operates fast and capable of holding more data than CD and Floppy.<br />
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<b><span style="color: #0b5394;">External Hard Disk</span></b><br />
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An external hard drive is a portable storage device that can be attached to a computer through a USB. External hard drives typically have high storage capacities than pen drives and are often used to back up computers or serve as a network drive.</div>
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