Introduction to the five components of the computer.

1. Components of the
Computer

2. A computer does mainly the following four functions :
 Receive input – Accept information from outside through various input
devices like the keyboard, mouse etc.
 Process information – Perform arithmetic or logical operations on the
information.
 Produce output – Communicate information to the outside world
through output devices like monitor, printer etc.
 Store information – Store the information in storage devices like hard
disk, floppy disks etc.
There are five components of the computer which perform the previous
four functions :

3. CENTRAL PROCESSING UNIT (CPU)
The part of the computer that executes program instructions is
known as the processor or central processing unit (CPU). CPU
has two parts – the control unit and the arithmetic logic unit.
In a microcomputer, both are on the microprocessor chip.
CPU
Microprocessor

4. Control Unit
 The control unit tells the rest of the computer system how to
carry out a program’s instructions.
 It directs the movement of electronic signals between memory
– which temporarily holds data, instructions and processed
information – and the ALU.
Arithmetic Logic Unit
 Performs basic arithmetic operations such as addition and
subtraction.
 Performs logical operations such as AND, OR, and NOT.
 Most modern ALUs have a small amount of special storage units
called registers that can be accessed faster than main memory.

5. Input Unit
 An input device is any machine that feeds data into a
computer.
 Computer receives or accepts information as input from
the user for the further processing.
Keyboard Mouse
Speakers Touchpad

6. Memory
RAM and ROM
Memory – also known as the primary storage or main
memory – is a part of the microcomputer that holds data
for processing, instructions for processing the data.
Random Access Memory (RAM)
A type of computer memory
that can be accessed randomly.
Read Only Memory (ROM)
A type of computer memory on
which data can be prerecorded.

7. Output Units
 A device through which results stored in the
 computer memory are made available outside the
computer system.
 It produces and communicate information to the user
through output devices like monitor, printer etc.
Monitor Printer