Parts of Computer : A computer consists of the major components, i.e., input unit, central processing unit, and output unit. Diagrammatically, these components may be presented as follows:
1. Input Unit: Input unit is controlling the various input devices which are used for entering data into the computer. The mostly used input devices are keyboard, mouse and scanner. Other such devices are magnetic tape, magnetic disk, light pen, bar code reader, smart card reader etc. Besides, there are other devices which respond to voice and physical touch. Physical touch system is installed at airport for obtaining the online information about departure and arrival of flight. The input unit is responsible for taking input and converting it into binary system.
2. Central Processing Unit (CPU) : The CPU is the control center for a computer. It guides, directs and governs its performance. It is the brain of the computer. The main unit inside the computer is the central processing unit. Central processing unit is to computer as the brain is to human body. This is used to store program, photos, graphic and data and obey the instructions in program.
It is divided into three sub-units:
- Control Unit: Control unit controls and coordinates the activities of all the components of the computer. This unit accepts input data and converts it into computer binary system.
- Memory Unit: This unit stores data before being actually processed. The data so stored is accessed and processed according to instructions which are also stored in the memory section of computer well before such data is transmitted to the memory from input devices.
- Arithmetic and Logic Unit : It is responsible for performing all the arithmetical calculations and computations such as addition, subtraction, division and multiplication. It also performs logical functions involving comparisons among variable and data items.
4. Output Unit : After processing the data it ensures the convertibility of output into human readable form that is understandable by the user. The commonly used output devices include like monitor also called Visual Display Unit, printer, etc.
