Computer Hardware, Study Notes, Material - All Teaching Exams

By Neha Joshi|Updated : August 26th, 2022

In this article, we should read related to the Computer Hardware, Important for the Super TET Teaching exam.

Computer hardware can be explained as the physical parts of a computer such as a keyboard, mouse, and monitor. These parts of the computer are easily visible but some parts of the computer are hard to see from the outside.

Components of Computer Hardware

All the components of the hardware system can be divided into three categories on the basis of their functions.

  1. Input Devices
  2. Output Devices
  3. Components of the System Unit.

Input Devices

Any device that allows a user to give instructions or enter data to the computer, in order to carry out various different tasks is called an input device.

Example: Keyboard, Mouse, Scanner, Joystick, Graphic tablet, Barcode reader, Touch Screens, Webcam, etc.

Output Devices

Any device that shows a user the produced output of their instructions in a user-readable format is called an output device.

Example: Monitor, Speaker, Printer, Fax machine, Projector, Xerox Machine, Plotter, Headphones, etc.

Components of the System Unit.

The system unit is a major part of the computer and it contains all the essential components such as motherboard, CPU, memory chips, and SMPS. Its function is to hold the various small components and keep them intact in their positions.

  • Motherboard

The motherboard is the main board consists of many important components of the computer system such as the processor/CPU, memory chips, sound card (that lets us play music), and graphic card (allows us to see images & videos). It also allows all these components to receive power and communicate with each other to carry out different functions.

  • Central Processing Unit (CPU)

The CPU is also known as the brain of the computer system. It is responsible for processing the data & instructions given by the user through an input device and to give relevant results on an output device. The speed of a working CPU is measured in Hertz.

The CPU has three parts:

  1. Arithmetic Logic Unit (ALU)
    An ALU is a digital circuit that performs all the arithmetic & logical operations such as doing mathematics and logical reasoning of values & symbols.
  2. Control Unit
    The control unit is responsible for controlling and directing the flow of data given by a user to the CPU or storage depending on the user’s instructions. It also tells the ALU what operation to perform on the given data.
  3. Register
    A register is the small amount of storage that comes within the CPU for storing the instructions to process an input and to store the output processed by the ALU.


Computer memory, also known as storage is the space where data is processed and the given instructions for processing are also stored here.

It is classified into two types:

1. Primary Memory

It is also known as the main memory of a computer as it is placed inside the motherboard of the computer system in the form of memory chips. Hence it holds all the data & instructions that are working on the computer. It has a limited capacity & data is lost when the power goes off. Primary memory can be directly used by the CPU for processing or storing an input or output.

There are two types of primary memory chips in the motherboard named RAM & ROM.

  • RAM - Random Access Memory
  1. It is an internal memory of the computer system.
  2. It is a read/write memory, which means data can be written onto & read from the RAM.
  3. When you turn on a computer, it loads the operating system into the RAM. So when you work on a program you are actually working on the data loaded in the RAM.
  4. It is a volatile memory which means the data is only stored until the computer is working and if it switches off the data is lost.
  5. The amount of RAM installed in a computer system determines the size & number of programs the computer can run simultaneously.
  6. RAM comes in two types that are DRAM (DYNAMIC RAM) and SRAM (Static RAM).
  • ROM - Read-Only Memory
  1. It is an internal read-only memory which means data can be read from it but a user cannot write on it.
  2. It has prerecorded data and information is permanently stored in the ROM by the manufacturers.
  3. It is a non-volatile memory which means it retains the data even when the computer switches off.
  4. ROM contains the instructions that are required to start a computer.
  5. ROM is used to store a special software that helps load the operating system when it is switched on called BIOS (Basic Input/Output System).
  6. ROM chips are also used in various other electronic items like a washing machines & microwave ovens.
  7. ROM comes in four types that are MROM (Masked ROM), PROM (Programmable ROM), EPROM (Erasable & Programmable ROM) & EEPROM (Electrically Erasable & Programmable ROM).

2. Secondary Memory

It is also known as the external storage/memory of a computer. It is a non-volatile memory that is used to store data permanently. CPU cannot directly access secondary memory and it is accessed via input-output methods. Hence the data is first transferred to the main memory and then accessed by the CPU. Secondary memories come in many different storage capacities and are used to store additional data. There are disk drives & tape drives present to access additional storage such as CDs & DVDs.

A hard disk is the main storage device present in the computer system. It can store a huge amount of data and all the work done in a computer can be stored inside the hard disk.

Example: Hard disk, CD-ROM, Floppy, etc.

SMPS - Switched Mode Power Supply

It is responsible for converting the incoming electricity from the switch into the right voltage and supplying it to all the parts of a system unit.


Ports are the inlet present on the system that lets you connect various input-output devices such as a keyboard, mouse, earphones, printer, etc.

This article tends to be beneficial for the following exams - REETUPTETCTETSuper TETDSSSBKVS etc.


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