Describe the main functional units of a digital computer

There are several types of computer system, but each can be broken down into the same functional units. Each unit performs specific functions.

The major functions of each unit are:- 

(i) Input unit: Through this unit, a complete set of instructions and data is fed into the computer system and into the memory unit, to be stored until needed. The information typically enters the input unit from a keyboard or a disk.

(ii) Memory unit: The memory stores the instructions and data received from the input unit. It stores the results of arithmetic operations received from the arithmetic unit. It also supplies information to the output input.

(iii) Control unit: This unit takes instructions from the memory unit one at a time and interprets them.

(iv) Arithmetic logic unit: All arithmetic calculations and logical decision are performed in this unit, which can then send results to the memory unit to be stored.

(v) Output unit: This unit takes data from the memory unit and prints out, displays, or otherwise presents the information to the operator.