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What is a computer? Components and types of computer

Many people define computer in different ways but the key words should be observed, whichever way you define it.

An old computer

What is a computer?

A computer can be defined as an electronic device that accepts data as an input, processes that data and give out information as a result. It also capable of storing that data and can retrieve that stored data whenever needed.

All computers have two things in common and these are hardware and software.

1. Hardware

Computer hardware are all physical parts of a computer that you can touch and feel. They together with software make up a computer. 

Computer hardware are of two categories:
i. Computer main parts
ii. Computer peripherals

i. Computer main parts are the ones which without them a computer can not function. For example a processor, motherboard, hard disk, RAM and power supply.

ii. Computer peripherals are the parts of a computer which without them a computer can still function. For example a mouse, keyboard, printer, scanner etc.

The hardware parts of a computer are grouped as input devices, processing devices, storage devices and outputting devices.

Input devices are the ones which are used to enter data into the computer for it to process. Examples of input devices are keyboard, camera, Mouse, Joy Stick, Light pen, Track Ball, Scanner and Microphone.

Output devices are the ones which are used to display or reflect the processed data from a computer. Examples of output devices are speaker, monitor and printers.

Processing devices are the ones which are responsible for processing data within a computer. Examples of processing devices are CPU, motherboard and GPU.

Storage devices are the ones which are responsible to store data in the computer. Examples of storage devices are hard disk, ROM and RAM.

COMPUTER COMPONENTS AND THEIR FUNCTIONS

i. Processor - Is considered as the brain of the computer, processing data and producing information.

ii. Hard disk - Is used for storing data permanently.

iii. Random Access Memory (RAM) - For storing data temporarily or for a short time.

iv. Compact disk read only memory (CD-ROM) - For reading and writing data.

v. Power supply - For supplying and regulating power as needed by the computer.

vi. Screen/monitor - For displaying information.

vii. Keyboard - For entering data into the computer.

viii. Motherboard - For holding the inside parts of computer and also for providing platform for power supply to the parts attached to it.

ix. Mouse - For pointing/selecting and moving objects on the screen.

2. Computer Software

It is a collection of instructions that enable a user to interact with a computer, its hardware or perform tasks. Also it can be defined as set of instructions which tells a computer what to do and how to do it, and enable a user to perform a certain task. Without software, computers would be useless. For example, without your Internet browser, you can not surf the internet and without an operating system, the browser can not run on your computer.

categories of software

There are three main types of software, although some do say there are two types.
These are,
  • System software,
  • Application software and
  • Utility software.

System software is a collection of one or more programs used to control and coordinate the hardware and other application software. Generally the system software may perform the following functions.
  • Controls and monitors the proper use of various hardware resources like CPU, memory, peripheral devices like monitor, printer etc.
  • Supports the execution and development of other application softwares.
Few examples of system software are, Operating system (OS), Programming language translators, Compiler and Interpreters.

Application software is a collection of one or more programs used to solve a specific task. Generally software used in banking industry, airline/railway reservation, generation of telephone or electricity bills etc, all fall under application software.
Few examples of application software are, word processing software, spreadsheet software, database software, education software, entertainment software.


Utility software are programs that help the user in system maintenance tasks and in performing tasks of routine nature. Utility programs help the users in disk formatting, data compression, data backup, scanning for viruses etc. Examples of utility software are, anti-virus, registry cleaners, disk defragmenters, data backup utility, disk cleaners.

TYPES OF COMPUTER

There are basically five types of computers and these types normally base on the function and size of the computer. Computers support from a single user and thousands of them depending on their capacities to handle the users.

The following below are types of computers.
  • Microcomputer
  • Workstation
  • Minicomputer
  • Mainframe
  • Supercomputer

Microcomputer

A personal computer is one of the microcomputers which can be defined as a small, relatively inexpensive computer designed for an individual user. PCs are based on the microprocessor technology that enables manufacturers to put an entire CPU on one chip. Businesses use personal computers for word processing, accounting, desktop publishing, and for running spreadsheet and database management applications. At home, the most popular use for personal computers is playing games and surfing Internet.

Workstation

Workstation is a computer used for engineering applications (CAD/CAM), desktop publishing, software development, and other such types of applications which require a moderate amount of computing power and relatively high quality graphics capabilities.
Workstations generally come with a large, high-resolution graphics screen, large amount of RAM, inbuilt network support, and a graphical user interface. Most workstations also have a mass storage device such as a disk drive.

Minicomputer

It is a mid size multi-processing system capable of supporting up to 250 users simultaneously. They are mostly used by small organizations. They can also be used in large companies to accomplish
certain tasks in individual departments.
For instance, they can be used within the production department to monitor the production process.

Mainframe

Mainframe is very large in size and is an expensive computer capable of supporting hundreds or even thousands of users simultaneously.
Mainframe executes many programs concurrently and supports many simultaneous execution of programs.

Supercomputer

Supercomputers are one of the fastest computers currently available.
They are very expensive and are employed for specialized applications that require immense amount of mathematical calculations. For example, weather forecasting, scientific simulations, fluid dynamic calculations, nuclear energy research, electronic design, and analysis of geological data.

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