Computer Hardware

The term computer hardware refers to all tangible or physical parts of a computer. All the parts which you can see and touch on your computer are hardware. Computer hardware consists of input and output devices, Central processing unit and backing storage.

Common input devices include Mouse and Keyboard. A keyboard is used for inputting data by typing instructions for the computer to process. When a key is pressed on the keyboard, an electrical signal is generated and sent to the Central Processing Unit for it to manipulate the instruction.

A Mouse enables a pointer to move around the desktop by selecting or pointing at options.

The Central processing Unit interprets and processes data. It is commonly referred to as the brain of the computer because its functions resemble those of human brain. Composition of the Central Processing Unit is as follows:

Control Unit whose main function is to control the sequence of manipulating instructions on your computer.

Arithmetic/Logic Unit whose core function is to perform all mathematical and logical calculations.

Memory Registers which act like temporal storage area of data which is going to be processed.

Random Access Memory or RAM is a temporary storage area. It stores data for the time when the computer is on power. In this case, RAM is referred to as volatile because when the computer is switched off, the whole data is lost. It is recommended that all data MUST frequently be saved on your computer .

Read Only Memory or ROM is non-volatile which means that data can not be lost even when the computer has been turned off.

Output devices
These are used to take data from the computer to the user. Output devices include:

Visual Display Unit
It is commonly referred to as computer monitor. It displays all data that is typed on the keyboard and all data that has been processed by the Central processing Unit. It displays the soft copy of what has been typed on the keyboard or kept through other media.

A printer
It gives a hard copy of what is displayed on the Visual Display Unit. The print-out is a result of instructions given to a computer on that articular task.

Backing storage devices
They keep data for as long as you need it. Some backing storage device can be rewritten to while some are not. Examples of such devices include magnetic tapes, disks, cd's etc.