Computer System — Question 20

A computer system comprises of five basic components:

1. Input Unit — An input unit takes the input and converts it into binary form so that it can be understood by the computer. For example, keyboard, mouse etc.
2. Output Unit — It converts the output in binary form to human readable form. For example, monitor, speakers etc.
3. Central Processing Unit (CPU) — It is responsible for processing the data and instructions. It consists of two parts:
   1. Arithmetic and Logic Unit (ALU) — It performs all the four arithmetic operations (addition, subtraction, multiplication and division) and some logical operations (less than, greater than, less than equal to, greater than equal to, equal to, not equal to).
   2. Control Unit (CU) — It acts as a supervisor by controlling and guiding the operation taking place.
4. Primary Memory — It is the internal volatile­ memory where data and instructions are stored during processing. It is of two types: Random Access Memory (RAM) and Read Only Memory (ROM).
5. Secondary Storage Unit — It refers to the external storage devices which provide permanent memory to the computer system. For example, hard disk, compact disk, flash drive etc.