Extension Name of Some Files

A Website Window To Focus Upon Complete Computer Education

Windows Operating System

A Website Window To Focus Upon Complete Computer Education

Data Communication

A Website Window To Focus Upon Complete Computer Education

Some Abbreviations In Computer

A Website Window To Focus Upon Complete Computer Education

What Is The Internet

A Website Window To Focus Upon Complete Computer Education

Dec 13, 2012


SMPS(switch mode power supply): The power supply supplies power to every single part of the PC. The main function of the power supply is to convert them
230 volt AC into 3.3 volts, 5 volt and 12 volt DC power that the system requires for the operations. In addition to supplying power to run the system, the power supply also ensures that the system does not run unless the power supplied is sufficient to operate the system properly. The power supply completes internal checks and tests before allowing the system to start. If the tests are successful, the power supply sends a special signal to the motherboard called power_good. If this signal is not present continuously, the computer does not run. Therefore, when the AC voltage dips and the power supply becomes stressed or overheated, the power_good signal goes down and forces a system reset or complete shutdown.


features of SMPS

* Receive up to 230-volt ac.
* Step down the power.
* Convert AC to DC.
* Supply power to a different device of the computer system.
* Low working temperature.
* Ultra compact open frame switching power supply.
* Universal input.

Types os SMPS:
1.AT(Advanced Technology)SMPS:
AT stands for Advanced Technology. These are all old SMPS. They have 12 pin power connector, this is called AT power connector. They were used in Pentium-I, Pentium-II, Pentium-III and Pentium MMX CPUs.

2.ATX(Advanced Technology Extended):
ATX stands for Advanced Technology Extended. They have 20 pin power connector, this is called as the ATX power connector. They were used in Pentium-III, Pentium-IV and AMD CPUs.

3.BTX(Balanced Technology Extended):
BTX stands for Balanced Technology Extended. They have 24 pin power connector, this is also called as the ATX power connector. It has 15 pins SATA power connectors. They are used in Dual Core, Core2duo, Quad Core, I-3, I-5, I-7 and latest AMD CPUs.


Dec 5, 2012


The internet sometimes called simply "the net".The Internet is a huge number of computers that are worldwide connected to each other.these computers are situated in many different countries and are connected through telephone lines, cables in the ground and even satellites in space. 

                           On a lot of these computers, people have published information, pages with text and pictures. These pages are called 'websites'.These are millions of websites on the internet, with an enormous amount of information which you can view and use for your reading, research or fun.


1. Get information online about a university, college, and school.
2. Download games, videos, pictures, computer programs and other files.
3. Send instant messages.
4. Look information about a place.
5. Pay bills online.
6. Look for information on Wikipedia.
7. Look religious or spiritual information.
8. Play online games.
9. Listen to music online.
10. Search for information about someone you know or might meet.
11. Share files from own computer with others.
12. Participate in an online auction.
13. Chat in a chat room or in an online discussion.
14. Make a donation to a charity online.
15. View live images online of a remote location or person, using a webcam.
16. Use an online social networking site like Facebook, Myspace, Orkut etc.
17. Sell something online.
18. Visit an adult website.
19. Take a class online for higher education.
20. Make a phone call online.
21. Sell or buy bonds, stocks or mutual funds.
22. Go to a dating website or other site where you can meet people online.
23. Sending or reading email.
24. Use a search engine to find information.
25. Search for a map or driving directions.
26. Check the weather.
27. Get news, health, medical and travel information.
28. Make or buy a reservation for travel.
29. Look up phone number or address.
30. Do any banking online.
31. Do any types of research for your job.
32. Look online for information about a job.
33. Get sports scores and information online.  


 .com for commercial organizations.
 .org for non-profit organizations.
 .net for network access provider.
 .mil for military installations.
 .gov for government agencies.
 .edu for educational institutions.
 .name for personal sites.
 .info for commercial and personal.
 .biz for commercial and personal.
 .int for organizations established by international treaty.


The term WWW refers to the world wide web or simply the web. The world wide web consists of all the public websites connected to the internet worldwide, including the client devices that access web content. The WWW is just one of many applications of the internet and computer networks.

The world wide web is based on three technologies ...

a> HTML(hypertext markup language)
b> HTTP(hypertext transfer protocol)
c> web servers and web browsers

Researcher Tim Berners-Lee led the development of the original world wide web in the late 1980s and early 1990s. He helped build prototypes of the above web technologies and coined the term "WWW". Websites and web browsing explode in popularity during the mid-1990s.


Every web page or internet resource accessible through the WWW has a unique name, this is URL(uniform resource locator). The URL identifies and locates a resource so that a web browser can access it directly. A URL is a type of internet address.

           URL strings consist of three parts ......
a. Network protocol.
b. Hostname or address.
c. File or resource location.


An internet service provider is an organization that maintains a high-speed network of cables connected to the internet. This organization usually owns more than one powerful computer that is directly connected to the network forming the internet.


It is basically a program that runs on an internet connected computer and provides access to WWW resources.


The process of navigating among the document is called browsing. The users need to have client software such as Netscape Navigator to actually retrieve and browse the information on the WWW. WWW supports many kinds of documents such as text, pictures, video, and audio. Sometimes it is referred to as net surfing.


A Homepage is a document that serves as the initial point of entry to a web of related documents. It contains introductory information, hyperlinks to related resources and navigation buttons to help users find their way among the various documents.


The computer that is requesting for some service from another computer is called the client.


A web server is a program that accepts requests for information framed according to the hypertext transport protocol (http). The server processes these requests and sends the requested document. when you can access a WWW server, the document is transferred to your computer and then the connection is terminated. This reduces network traffic by not having to hold on to a line, which you read a document.


A collection of documents inter-linked by hyperlinks is called the web. A web page is synonymous with web documents. It is not the same as a page on your screen. It is also defined a hypertext information system.


A hyperlink allows you to view information without using complex commands and without even knowing the source of the information. A hyperlink includes within it all the information needed to retrieve information or connect to a specific internet resource. Much of the excitement about the world wide web is due to its extensive use of hyperlinks.


Is a formal definition of a language that two computers use to communicate. This definition describes acceptable messages and outlines the rules that two computers must follow to exchange those messages.


When a hyperlink is attached to text, it is called hypertext. Hypertext is a method of preparing and publishing the text in which users can choose their own paths for the material. The text is broken into small units such as single pages called nodes. Then hyperlinks are embedded into the text. Typically the users have a GUI on which he clicks a button to navigate through the different pages.


A markup language is a set of formatting codes that effects that the way preset information will be displayed. It is used to create hypertext markup language documents. It is not a programming language. Only the presentation, but not the contents. The information remains static all the documents that you view on the WWW are created using HTML.

Dec 3, 2012


keyboard shortcuts:

F2                                   = Edit the selected cell.
F5                                   = Go to a specific cell.
F7                                   = Spell check selected text and document.
F11                                 = Create chart.
ctrl+A                             = Select all.
ctrl+B                             = Bold.
ctrl+C                             = Copy.
ctrl+F                              = Find.
ctrl+G                             = Go to.
ctrl+H                             = Replace. 
ctrl+I                              = Italic.
ctrl+K                            = Insert link.
ctrl+N                            = New workbook.
ctrl+O                            = Open workbook.
ctrl+P                            = Print dialog.
ctrl+S                            = Save.
ctrl+U                           = Underline.
ctrl+V                           = Paste.
ctrl+Z                           = Undo.
ctrl+Y                           = Redo.
ctrl+X                           = Cut.
ctrl+5                            = Strikethrough text.
ctrl+F3                          = Define name.
ctrl+F4                          = Exit excel.
ctrl+F6                          = Switch between open workbooks.
ctrl+F9                          = Minimize current window.
ctrl+F10                        = Maximize current window.
shift+F1                        = Activate help on item.
shift+F2                        = Insert comments.
shift+F3                        = Insert function.
ctrl+shift+;                   = Enter the current time.
ctrl+;                            = Enter the current date.
ctrl+page down            = Move to next worksheet.
ctrl+page up                 = Move to previous worksheet.
ctrl+shift+#                  = Number format:date.
ctrl+shift+@                = Number format:time.
ctrl+shift+!                  = Number format:commas.
ctrl+shift+$                 = Number format:currency.
ctrl+shift+%                = Number format:percentage.
ctrl+shift+^                 = Number format:scientific.
ctrl+space                   = Select entire column.
shift+space                  = Select entire row.
ctrl+arrow key            = Move to next section.

MS Excel


double-click on a cell                           = Edit the cell contents.
double click on a row/column divider = Adjust height/width to autofit.
 click on row/column divider then drag = Adjust height/width of the row/column.

ctrl+mouse wheel                              = Zooms in or zooms out of the document.

hold shift+click the cells                  = Select multiple cells.

triple click                                        = Select the entire contents of the cell.

Nov 24, 2012


INTRODUCTION: The first electronic computer was designed and built at the University of Pennsylvania based on vacuum tube technology.

Vacuum tubes were used to perform logic operations and to store data. Generations of computers have been divided into five according to the development of technologies used to fabricate the processors, memories and I/O units.


Example- ENIAC = Electronic Numerical Integrator and Calculator.
               EDSAC = Electronic Delay Storage Automatic Calculator.
               EDVAC = Electronic Discrete Variable Automatic              Computer.
              UNIVAC = Universal Automatic Computer IBM 701.
              IBM-650 etc.

The technology used:  Vacuum tube.

First Generation Computer

1. Vacuum tubes were used- basic arithmetic operations took few milliseconds.
2. Bulky
3. Consume more power with limited performance.
4. High cost.               
5. Uses assembly language- to prepare programs. These were translated into machine level language for execution.
6. Mercury delay line memories and electrostatic memories were used.
7. Fixed point arithmetic was used.
8. 100 to 1000 fold increase in speed relative to the earlier mechanical and relay based electromechanical technology.
9. Punched cards and paper tape were invented to feed programs and data and to get results.
10. Magnetic tape/magnetic drum was used as secondary memory.
11. Mainly used for scientific computations


1. Only vacuum tubes are required.


1. Generates heat.
2. Airconditioning required.
3. Large in size.
4. Unreliable.
5. Constant maintenance required.


Example-IBM 7030 , Digital Data Corporation's PDP 1/5/8 , Honeywell 400. CDC-1604, CDC-3600, UNIVAC-1108 etc.

The technology used:  Transistor.

Second Generation Computer

1. Transistors were used in place of vacuum tubes.
2. Small in size                                                                                3. Lesser power consumption and better performance.
4. Lower cost.
5. Magnetic ferrite core memories were used as the main memory which is a random-access nonvolatile memory.
6. Magnetic tapes and magnetic disks were used as secondary memory.
7. Hardware for floating point arithmetic operations was developed.
8. Index registers were introduced which increased the flexibility of programming.
9. High-level languages such as FORTRAN, COBOL etc. Were used- compilers were developed to translate the high-level program into corresponding assembly language program which was then translated into machine language.
10. Separate input-output processors were developed that could operate in parallel with CPU.
11. Punched cards continued during this period also.
12. 1000 fold increase in speed.
13. Increasingly used in business, industry and commercial organizations for preparation of payroll, inventory control, marketing, production planning, research, scientific and engineering analysis and design etc. 


1. Less heat generation.
2. Smaller in size compared to the first generation.
3. More reliable.
4. Faster in action.


1. Airconditioning required.
2. Maintenance required.


Example- System 360 Mainframe from IBM, PDP-8 Minicomputer from Digital Equipment Corporation, Honeywell-6000 series, TDC-316 etc.

The technology used:  Integrated Circuit(IC).

Third Generation Computer

1. ICs were used.
2. Small-scale integration and medium scale integration technology were implemented in CPU, I/O processors etc.
3. Smaller and better performance.
4. Comparatively lesser cost.
5. Faster processors.
6. In the beginning, magnetic core memories were used. Later they were replaced by semiconductors memories.
7. Introduced microprogramming.
8. Microprogramming, parallel processing, multiprogramming, multi-user system etc were introduced.
9. Operating system software was introduced.
10. Cache and virtual memories were introduced.
11. High-level languages were standardized by ANSI. Example- ANSI FORTRAN, ANSI COBOL etc.
12. Database management, multi-user application, online systems like closed-loop process control, airline reservation, interactive query systems, automatic industrial control etc emerged during this period.


1. Smaller in size.
2. Lower heat generation.
3. Less power requirement.
4. More reliable than the first and second generation.
5. Faster than the first and second generation.
6. Low maintenance cost.
7. Easily portable.
8. Cheaper commercial production.


1. Manufacturing difficulty.
2. Airconditioning required.


Example- Intel's 8088, 80286, 80386, 80486..... , Motorola's 68000, 68030, 68040 , Apple 2 , CRAY 1/2/X/MP, DEC-10, STAT-1000, PDP-11 etc.

The technology used:  Large and very large scale integrated circuit(LSIC and VLSIC).

Fourth Generation Computer

1. Microprocessors were introduced as CPU- complete processors and a large section of main memory could be implemented in a single chip.
2. Tens of thousands of transistors can be placed in a single chip.
3. CRT screen, laser and inkjet printers, scanners etc were developed.   
4. Semiconductor memory chips were used as the main memory.
5. Secondary memory was composed of hard disks- floppy disks and magnetic tapes were used for backup memory.
6. Parallelism, pipelining cache memory, and virtual memory were applied in a better way.
7. LAN and WANs were developed.
8. Introduced C language and Unix OS.
9. Introduced graphical user interface.
10. Less power consumption.
11. High performance, lower cost and very compact
12. Much increase in the speed of operation.


1. Smaller in size.
2. Portable.
3. No air conditioning required.
4. Practically maintenance free.
5. Cheaper and reliable.
6. Less power requirement.
7. General purpose and much cheaper.


1. Complex software.
2. The highly sophisticated technology required for manufacturing LSIC and VLSI chips.


Example- IBM Notebooks, Pentium - 1/2/3/4/dual core/quad core..., SUN workstations, Origin 2000, PARAM 10000, IBM SP/2, Notebook, Ultrabook, Chromebook, Laptop etc.

The technology used:  KIPS(knowledge information processing system) and PROLOG(programming in logic language).

Fifth Generation Computer

1. Generation number beyond  IV, have been used occasionally to describe some current computer system that has a dominant organizational or application driven feature.
2. Computers based on artificial intelligence are available.
3. Computers use extensive parallel processing, multiple pipelines, multiple processors etc.
4. Massive parallel machines and the extensively distributed system connected by communication networks fall in this category.
5. Introduced ULSI technology- Intel's Pentium 4 microprocessor contains 55 million transistors millions of components on a single IC  chip.
6. Superscalar processors, vector processors, SIMD processors, 32-bit microcontrollers and embedded processors, digital signal processors etc have been developed.
7. Memory chips  2 GB, hard disk drivers 360 GB  and optical disks 27 GB are available.
8. Object-oriented language like JAVA  suitable for internet programming has been developed.
9. Portable notebook computers introduced.
10. Storage technology advanced- large main memory and disk storage available.
11. Introduced world wide web.
12. New operating systems developed- Windows XP/7/8...., LINUX etc.
13. Got hot pluggable features- which enable a failed component to be replaced with a new one without the need to shutdown the system, allowing the uptime of the system to be very high.
14. The recent development in the application of internet is the Grid technology which is still in its upcoming stage.
15. Quantum mechanism and nanotechnology will radically change the phase of computers.


1. Will work parallelly.
2. Will have the capability of performing multiple tasks at a time.
3. Will have the capability of knowledge processing.
4. Will be a knowledge information processing system.
5. Will process basic intelligence.


1. Not yet known.

Nov 22, 2012


Another name of software or program. Some common types of applications are word processors, spreadsheets, databases etc.

A mistake or unexpected occurrence in a piece of software or hardware.


The area of the mac's memory that holds what you last "cut" or "copied". You can pass the contents of your clipboard into documents.



An accessory that allows you to set things like how sounds, monitor, backgrounds and how fast the insertion point blinks.

5>CPU(central processing unit): 

The central processing unit is made up of circuitry and computer chips, which perform the computer's calculations. The CPU is often what people call the box in which the all of the computer's circuitry is housed.


The computer's interface uses a desktop metaphor. The desktop is the gray or colored background you see on the screen when you start your computer. It is the place where you do your work by handling icons and working with pictures that represent your files, folders, and disks.


Electronic mail allows a computer user to send messages instantaneously to another user's electronic mailbox. To send an e-mail to someone, you must have their e-mail address and you must be connected to a network.


In all applications, the file menu contains commands for opening, saving, printing and closing documents, quitting the application etc.


A magnetic storage medium about 3.25 in size, which can be recorded, erased and used over and over again. A floppy disk holds can hold 1.4 megabytes of information.


The physical components of a computer system. Those things which you can touch.


A rigid, usually non-removable disk or the disk drive that houses it. Hard disks store much more data and access it much more quickly than floppy disks.


Opening an application.


The retention of information electronically, on chips. See a difference in storage. There are two main types of memory: RAM, which is used for the short-term retention of information and ROM, which is used store programs that are seldom changed.


The horizontal area across the top of the screen that contains the menu titles.


One million cycles per second. a unit of measurement to compare clock speed of computers. The higher the number, the faster the computer.


A device that adapts a computer to voice communications(telephone) network. The modem converts the digital pulses from a computer to audio tones, which can be transmitted by a telephone system.


Two or more computers and associated devices that are connected by communications hard wire(phone wire, network cable, satellite etc.).


Inserting something into a document from the clipboard by choosing paste from the edit menu.


To "reboot" means to restart the computer.


The instructions that tell a computer what to do. Also called programs or applications.


The long-term retention of information magnetically or optically. It persists after you turn your computer off. Compare this with memory.


A standard folder on Mac hard drives that contain the system file, the finder, and other system software.


Just like a floppy disk, except slightly thicker and more durable. A ZIP DISK can hold up to 100 megabytes of information. This is convenient for working with large files, especially graphics.


The basic software that controls a computer's operation.


Established in the 1960s by the US government, the internet was developed so that government agencies and universities could link research centers in response the perceived notion that the Soviet Union was becoming more advanced in the space race. The internet was created as a "de-centralized" network, meaning that there is no one place that makes up the internet. This was done to make sure the internet survived a nuclear war. Today, the internet is a vast collection of e-mail, Usenet groups, FTP sites, and websites, with millions upon millions of users from around the world.


A program that lets you read information(HTML documents) and navigate the world wide web.


A system in which people can communicate by typing messages. Unlike e-mail messages, chat messages are sent and received as you type.


A name was given to a host computer on the internet.


Pointing at an item on the screen, clicking with the left mouse button and while holding the mouse button down, dragging the item to another part of the screen.


An option on most websites that gives instructions on how to use the site. It is sometimes called  'about this site' or 'FAQ' (frequently asked questions).


A directory(list) of websites that are selected, categorized and organized by people.


A tool that uses various electronic techniques to visit, search, collect and organize data from websites. Google, Yahoo, Bing, Ask search engines to help you search.


The proper term for referring to web page address.


A computer file electronically stapled to an e-mail message and sent along with it.


The capacity of a network connection. Bandwith determines how much data can be sent along the networked wires. Bandwith is particularly important for internet connections since greater bandwidth also means faster downloads.


A small data memory storage area that a computer can use to instantly re-access data instead of re-reading the data from the original source, such as a hard drive. Browsers use a cache to store web pages so that the user may view them again without reconnecting to the web.


A tiny wafer of silicon-containing miniature electric circuits that can store millions of bits of information.


A software or hardware problem that causes information to be lost or the computer to malfunction. Sometimes a crash can cause permanent damage to a computer.


A text file sent by a web server that is stored on the hard drive of a computer and relays back to the web server things about the user, his or her computer, and/or his or her computer activities.


A collection of similar information stored in a file, such as a database of addresses. This information may be created and stored in a database management system.


To find and correct equipment defects or program malfunctions.


The pre-defined configuration of a system or an application. In most programs, the defaults can be changed to reflect personal preferences.


An electronic reading device that allows a person to view digitally stored reading materials.


Digital subscriber line. A method of connecting to the internet via a phone line. A DSL connection uses copper telephone lines but is able to relay data at much higher speeds than modems and does not interfere with telephone use.


A set of security programs that protect a computer from outside interference or access via the internet


FTP means file transfer protocol. A format and set of rules for transferring files from a host to a remote computer.


The main page of a website used to greet visitors, provide information about the site or to direct the viewer to other pages on the site.


A person with technical expertise who experiments with computer systems to determine how to develop additional features. Hackers are occasionally requested by system administrators to try and break into systems via a network to test security. The term hacker is sometimes incorrectly used interchangeably with the cracker. A hacker is called a white hat and a cracker a black hat.


Software programs that combine text and graphics with sound, video, and animation. A multimedia PC contains the hardware to support these capabilities.

A handheld computer.


Portable document format. A format presented by adobe acrobat that allows documents to be shared over a variety of operating systems. Documents can contain words and pictures and be formatted to have electronic links to other parts of the document or to places on the web.


A precise series of instructions written in a computer language that tells the computer what to do and how to do it. Programs are also called software or applications.


A computer that shares its resources and information with other computers, called clients on a network.


Exploring the internet.


Taking packets of information (sound or visual) from the internet and storing it in temporary files to allow it to play in a continuous flow.


A video camera, computer setup that takes live images and sends them to a web browser.

Nov 19, 2012


                               MS EXCEL- 2007(PRACTICAL)
MS Excel

    Start---All Programs---Microsoft Office---Microsoft Office Excel 2007.
or: Start---Run---Type(Excel)---Ok.


    Select the cell---Home---Fill Color---Select a Color.


    Select the Cell---Home---Border---Select(All Border).


    Adjust the Cell---Home---Wrap Text.


    Select the Cell---Home---Orientation---Select an Orientation.


    Select the Cell---Home---Merge and Center.


     A>SUM:               = Cell+Cell+Cell+Enter.
                            = Sum(Cell,Cell,Cell)+Enter.
                            = Sum(Cell:Cell)+Enter

   B>MULTIPLY:     = Cell*Cell+Enter.

   C>DIVIDE:          = Cell/Cell+Enter.

   D>SUBTRACT:    = Cell-Cell+Enter.


    Right-click on the row or column which previous you want to insert new one---Home---Insert.


    Select the row or column which you want to delete---Home---Delete.


      Select the database---Insert---Select a chart type---Select a design.


      Select the chart---Design---More---Select a design.


     Maximum number :
      =Max(Cell,Cell ....)Enter

   Minimum number :

    =Min(Cell,Cell ....)Enter


      Select the cell---Data---Data validation---Settings---Allow(List)---Type your list(Using Comma)---Ok.


      Customize quick access toolbar---More---Commands---Popular---Edit custom list---Type your list(Using Comma)---Add---Ok---Ok.


      Enter a value---Select that cell---Home---Fill---Series(Series in)Row or Column---Select(Liner)---Enter step value---Enter stop value---Ok.


      Select the database---Home---Sort and filter---Filter.


      Select the cell---Review---New comment---Type your comment.


      Select the cell that contains formula---Formulas---Trace precedent.




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