Input unit is used to feed any form of data to the computer, which can be stored in the memory unit for further processing. Example: Keyboard, mouse, etc.
Central Processing Unit
CPU is the major component which interprets and executes software instructions. It also control the operation of all other components such as memory, input and output units. It accepts binary data as input, process the data according to the instructions and provide the result as output.
The CPU has three components which are Control unit, Arithmetic and logic unit (ALU) and Memory unit.
The control unit controls the flow of data between the CPU, memory and I/O devices. It also controls the entire operation of a computer.
An Output Unit is any hardware component that conveys information to users in an understandable form. Example: Monitor, Printer etc.
The Memory Unit is of two types which are primary memory and secondary memory. The primary memory is used to temporarily store the programs and data when the instructions are ready to execute. The secondary memory is used to store the data permanently. The Primary Memory is volatile, that is, the content is lost when the power supply is switched off.
The Random Access Memory (RAM) is an example of a main memory. The Secondary memory is non volatile, that is, the content is available even after the power supply is switched off. Hard disk, CD-ROM and DVD ROM are examples of secondary memory.