A computer consists of following main components-
1. Input/Output Units
2. Central Processing Unit
3. Memory Unit
1. Input/Output Units-
The computer accepts coded information through input unit by the user, the devices used for this are keyboard, mouse etc., and then the processed result to the user is given by output devices like monitor, printer etc.
2. Central Processing Unit (CPU)–
CPU is often called ‘the brain of computer’. It is fabricated as a single Integrated Circuit (IC) and is also known as ‘microprocessor. It consists of following main sub-units
(A) ALU (Arithmetic Logic Unit) It executes all arithmetic and logical operations on the available data.
(B) CU (Control Unit) It directs the computer to carry out stored program instructions by communicating with the ALU and the registers.
3. Memory Unit
This unit is responsible to store programs or data on a temporary or permanent basis. It has
(1) Primary (main) memory It communicates
directly with the CPU. It includes
(a) RAM (Random Access Memory)
(b) ROM (Read Only Memory)
(ii) Secondary (auxiliary) memory It stores much larger amounts of data and information for extended periods of time. This includes CD, DVD, Blu ray disk, Pen drive, Hard disk drive, etc.
The main circuit board contained in any computer is called a ‘Motherboard’. All the other electronic devices and circuits of computer system are attached to this board like CPU, ROM, RAM, and PCI slots.