Quick Reference Study Notes for Computer Fundamentals

Computer Fundamentals

A computer is an electronic device which takes input from the user in form of numbers, text, image, video etc. , perform a sequence of operations and convert them into a meaningful output that can be understood by the user.

A computer has two primary categories-

  1. Hardware- It is the physical structure of the computer that is visible. It includes Monitor, Keyboard, Mouse etc. A computer’s hardware is an item that you can touch or physically see.

    1. Software- These are the programs that run on the Hardware to perform the operations of the computer. The software of computer tells the hardware what to do.


Main Parts of Personal Computer -

  1. Central Processing Unit (CPU) - CPU is the computer's, main heart. It performs all the operations. Its speed can be measured in MegaHertz (MHz) or GigaHertz(GHz).

  2. Common Input devices - Input devices are mainly used to provide input to the computer. Some common input devices are -

    1. Mouse - It is the handheld pointing device which controls the position of the cursor on the screen.

    2. Keyboard - The use of the keyboard is to give command or information to the computer by typing something.

    3. Microphone - It is used to give the input in form of audio to the computer.

  3. Common output devices - Output devices are used to get the output from the computer. Some output devices are:-

    1. Monitor - It somewhat looks and works like a TV screen. The monitor is only the half that makes the text and images appear on the screen the other half is the graphics card inserted in the motherboard.

    2. Printer- This device transfers the processed information on the printed paper.

    3. Speaker- Its main function is to transfer the information in form of audio.

      Memory - The main function of memory is to store the data or information that can be used by the user or the Operating system. Main types of memory are -

      1. RAM (Random memory access) - It is the computer’s main memory which is used to process memory. It stores the data as long as the power is on.

      2. ROM (Read Only Memory) - In this type of memory data is writing when we manufacture the memory hardware and after that, we can only read this memory. This is a write once and reads kind of memory.

Measuring the memory - We can measure the memory in many terms, some of them are given below -

  • Bit - It is the short name for Binary digit. It is the smallest memory unit.

  • Byte - Short name for binary digit eight. 1 byte is equal to 8 bits.

  • Kilobyte(K or KB) - 1 KB is equal to 1024 bytes

  • Megabyte(M or MB) - 1 MB is equal to 1024 kilobytes

  • Gigabyte(G or GB) - 1 GB  is equal to 1024 megabytes

  • Terabyte(T or TB) - 1 TB is equal to 1024 megabytes

Computer performance - Computer performance depends on many factors like the access speed of the RAM, Size of main memory and many more. Some of the factors are discussed below -

  • CPU Speed - CPU speed is the most important factor to determine the performance of the Computer.

  • RAM - Computer performance also depends on the RAM size. The more the RAM size the better the performance.

  • Multitasking - A computer can run multiple programs at once. So the more the number of programs running at a time the less the computer performance.

Software - Software is something that runs on the hardware. It is a collection of instructions which tells the computer what to do. Here are some basic used software in computer -

  • Graphical User Interface (GUI) - It uses the icons and pictures to show the programs and files

  • Operating System - It loads automatically when we start the computer and run almost everything in a computer.

  • Application programs- These are those programs which are used to accomplish a certain task. We need to install these programs explicitly. They are not preinstalled.


Network and the Internet -  Some command terms used in Network and internet are -


  • LAN - It is a Local area network which connects computers in a local and small area like a house or a building.

  • Internet- It is the biggest network in the world connecting millions of computers and devices. We can use it for many purposes like research, making an online purchase, and transferring online data or information.

  • World Wide Web - It is a hypertext system which operates over the internet. Hypertext is read by the web browsers which displays the web pages from web servers.

Storage/Memory Devices - These are used to share and transfer the information or data. These are very helpful in backing up our data.

A comparison between some storage devices -





Zip Disk

Slower than all other disks

100 to 250 Megabytes (MB)



Much slower than a hard disk

650 MB

Very expensive


Faster than a CD-ROM but not as fast as a hard disk

About 4 GB

Slightly more than a CD-ROM

Internal Hard disk

Very fast, most hard disks have an average access speed between 8 to 15 ms(milliseconds)

Some hard disks have more than 200 GB storage

Very inexpensive if we compare byte to byte

External Hard disk

Very fast but slower than an internal hard disk

Same as Internal Hard disks

Slightly more expensive than an internal hard disk.

Some windows tips:-

  • You can always press F1 if you need any kind of help.

  • If you made a mistake then you can try <ctrl> + <z> or you can go to Edit > Undo.

  • Not sure what to do with an object, just right click on that object and a list of options will pop up.

  • To create a new folder right click in an empty area and choose New > Folder or you can try a shortcut <ctrl> + <shift> + N.

  • To rename a file or folder or anything just right click on that object and choose Rename or select the object and press F2 and type the new name and press enter.

  • To delete an object right click on the object and select Delete or you can press the <delete> key after selecting the object.

  • To make a zip file select the file or folder and choose to Send To > Compressed zip folder.

  • If you want to open the command prompt in the current folder then click in the address bar at the top and type cmd and press enter.

  • To close any window click on the crossbar (x) on the right top corner of the window or you can press <alt> + F4.

  • You can also use <alt> + F4 to close the computer. It will open a window with options to shutdown the computer.

  • Here are some shortcuts to open applications using the Run prompt

To use all of these command press <window key> + R to open the run window and type these commands-


    • appwiz.cpl - To open the Install/Uninstall window

    • calc - To open the calculator

    • winword - To open the Microsoft word

    • excel - To open the microsoft excel

    • powerpnt - To open the microsoft powerpoint

    • notepad - To open the notepad

    • control - To open the control Panel


Parts of a typical window-

*NOTE : "This study material is collected from multiple sources to make a quick refresh course available to students."

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