Computer Hardware Explained

The hardware components of a computer are described and their functions explained.


The motherboard is a set of computer hardware components arranged so that they are physically connected and can easily communicate between each other. The motherboard makes it easy to attach all major hardware components of a computer. In what follows we will discuss these components.

CPU(Central Processing Unit)

The CPU is the most important piece of hardware in any computer. It manages all of the computer operations, calculations and tasks and manages, command and direct all the other components of a computer system.

Different CPU run at different speeds where the speed here is measured in terms of number of basic operations (cycles) per unit of time (usually the second). It is usually expressed in gigahertz. (1 gigahertz = 109 cycles / second)

Usually a computer with a higher CPU speed runs faster, however it is important to understand that there are other computer hardware items that greatly affect the speed of a computer.

The CPU has two major parts: The Arithmetic Logic Unit (ALU) which carry all arithmetic and logic operations and the Control Unit which manages and control all instructions.

RAM(Random Access Memory)

The RAM makes space available for your computer to read and write data to be accessed by the CPU. The computer reads data from a RAM faster than reading it from the hard drive and therefore adding more RAM to your computer makes it run a lot faster. RAM does not retain data when the computer is switched off hence the name of volatile memory.

ROM(Read Only Memory)

ROM contains data that cannot be modified and hence retain it even when the computer is switched off.


A modem is an electronic device that enables a computer to communicate with other computers over a network. A modem, for example, allows you to connect to the internet using cables and telephone lines. Information in a computer is in digital form whereas information sent over telephone lines is analog. The modem converts digital information into analog and vice versa.

Sound Card

A sound card enables the computer to produce sounds to be broadcast through speakers and also to process sounds received through a microphone.

Graphics Card

Graphics cards enable the computer to transform data into pictures to be displayed on the monitor. Many graphics cards now have their own RAM and "coprocessor" which make them faster at processing data and displaying it.

Input Devices

Output devices are used to enter data into the computer and also instruct it on what to do. The keyboard, mouse, touchpad, joystick, microphone and scanner are all examples of input devices.

Output Devices

The monitor, printer, speakers are all exmaples of output devices. Their function is to transform all output information into text, animated and static images and sound.