Fundamentals of Computer

Fundamentals of Computer

Fundamentals of Computer

Today we are presenting you a short note on Fundamentals of Computer. This is an important chapter before start to study about computer. So, here we simply describe the fundamentals of computer.

Definition of Computer

Computer is an electronics aperture which help to make calculations and controlling the operations that is expressible in numerical and logical both terms. Basic operations of a computer are

  • Arithmetic Operation
  • Logical Operation
  • Storage & Relatives

Information: Data is generally available in a raw or unprocessed form. Processed data is generally called Information.

Program: A program is defined as a sequence of instructions, which operate on data to perform tasks.

Execution of a Program: The Basic function performed by a computer is the execution of a program.

Components of a Computer

A. Input Unit

Computer accepts data for users through these units. It converts the instruction of users to machine language.
The input devices are Keyboard, Mouse, Jaystick, OCR (Optical Character Reader), Bar Code Reader, Bio-metric Sensor, Optical disk drive, Digital Camera, Scanner, Light Pen, MICR (Magnetic Ink Character Recognition), OMR (Optical Mark Recognition), Track Ball etc.

B. Central Processing Unit

The work of data processing of the computer done this part. It is called ‘the Brain’ of a computer. There are three parts in it.

i. Arithmetic and Logic Unit (ALU):

It performs all arithmetic and logic operations. ALU has two parts – Arithmetic Section & Logic Section.

ii. Control Unit:

This unit control all the command coming from input device. Its makes the output data. The Control Unit directs the ALU to perform specific arithmetic and logical functions on the data.

iii. Memory:

Its hold the input and output resulting data. Also hold the system and application software. There are two types of memory,

Types Computer Memory

a) Internal Memory (Primary): RAM, ROM
b) External Memory (Secondary): Hard Disk, CD, DVD, Pen drive.

Permanent Memory

It is a storable non volatile memory. It keeps all the data which store here even when power is off. E.g. ROM (Read Only Memory). ROM is a non-volatile memory.

  • Can’t read.
  • Can’t be written or changed.
  • Data not lost after the power off.

Point to Remember: ROM is where all active programs and data are stored. So, that they are readily available and easily accessed by the CPU.

Temporary Memory

It holds the all active programs data and resulting data . this type of memory easily accessible by CPU. E.g. RAM (Random Access Memory). RAM is a volatile memory.

  • Can read.
  • Can be written or changed.
  • Data lost after the power off.

Point to Remember: RAM is logical then that data stored on RAM can’t be changed.

Types of ROM

There are some qualities of ROM

  • PROM- Programmable Read Only Memory
  • EPROM- Erasable Programmable Read Only Memory
  • EEPROM- Electrically Erasable Programmable Read Only Memory (EEPROM is used for erasing & reconstructing the contents of ROM)
Types of RAM

There are some qualities of RAM.

  • DRAM- Dynamic Random Access Memory (DRAM is used for Refresh)
  • SDRAM- Synchronous Random Access Memory
  • EDORAM- Extended Data Output Random Access Memory
  • NVRAM- Non Volatile Random Access Memory

Point to Remember: Recycle Bin is a part of Hard Disk.

C. Output Unit

It displays the result of processed data to the user. E.g. VDU (Visual Display Unit), Speaker, Printer, Plotter etc.


Software is set of instructions that maintains and directs the computer to perform and process the input information. There are three type of software,

A. System Software

This software directs and makes a correlation among the various hardware of a computer. E.g. Windows XP/Vista/7/8/10, Linux, Unix, MS-Dos.

B. Application Software

It is a specific program defined applications. E.g. Windows Office, Paint, Games, Tally, Corel Draw, Adobe Photoshop etc.

C. Utility Software

It is used to debug the error in software and correct the data through the editor. E.g. Antivirus, PKZIP etc.


Firmware is the technology which has the combination of both Hardware & Software. E.g. BIOS (Basic Input/Output system) Chip inside a computer.

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