Block diagram of Computer:-

A block diagram of computer is also called basic diagram of computer or basic building block of computer

A block diagram of computer consists three sub unit that is 

1. Input unit :- input unit is the set of various unit devices into a computer system input unit can be defined as "devices by which user can inset the data into a computer system is called input devices.

    In other word we can say that "devices by which user can send the data into a computer system.

Example of input devices are :- Keyboard, Mouse,Joystick etc.


2. Storage Unit - Storage unit is also called memory unit , Memory unit deals with the set of various memory devices into a computer system memory unit can be defined as "devices to store data instruction program and processed it inside the computer system." 

I.  ALU :-  An arithmetic logic unit (ALU) is a digital circuit used to perform arithmetic and logic operations. It represents the fundamental building block of the central processing unit (CPU) of a computer.
in other word we can say that ALU performs arithmetic operation like "Addition(+), Subtraction (-) Multiplication(*), Division(/) and logical operation like"YES, NO, TRUE, FALSE .

II. CU :- CU stands for "Control Unit" and control the execution of all kinds of program with generating control signals.


III. ALU+CU(Central processing unit) also called CPU it is also called brain of computer. Sometimes referred to simply as the central processor, but more commonly called processor.

A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions.

3. Output Unit :- Output unit is the set of various output devices into a computer system output unit can be defined as "devices by which user get desired output is called output devices.

Example of output devices are :- Monitor, printer Plotter.etc