Basic Organization structure of Computer

The basic organization remains the same for all computer systems. A computer system consists of mainly three basic units; input unit, CPU(central processing unit), and output unit. CPU(Central Processing Unit) further has a Storage unit, Arithmetic logic unit, and control unit. 

All types of computers follow the same basic logical structure and perform the five basic operations for converting raw data into information; inputting, storing, processing, outputting, and controlling.

Components of Computer System

Following are the basic components of a computer:

1) Input Unit

2) Storage Unit

3) CPU(Central Processing Unit)

4) Output Unit

Input Unit

Devices that are used to enter data and instruction into the computer are called input unit. This unit creates a link between the user and the computer. A keyboard, a mouse, a scanner, etc are input device that enters data into a computer.

An input unit performs the following functions: 

1) It accepts or reads the data and instructions from the outside world.

2) It converts these data and instructions in computer acceptable form.

3) It supplies the converted data and instructions to the computer for further processing.

Storage Unit

All the data, instructions, intermediate results, and output are store in a storage unit.

Storage unit performs the following functions:

1) All the data and the instruction required for processing.

 
2) Intermediate results of processing.

3) Final results of processing before these results are given to an output device.

Types of Storage

There are two types of storage; Primary Storage and Secondary Storage.

Primary Storage:

Primary Memory is the main memory or internal memory of the computer system. It is directly accessed by the CPU(Central Processing Unit). It resides within the CPU. The primary memory is volatile in nature which means data does not exist if it is not saved when a power failure occurs. It is the fastest and expensive memory. RAM(Random Access Memory) is an example of primary memory.

Secondary Storage:

Secondary storage is also known as Auxiliary memory. It is non-volatile in nature which means it retains data when power is switched off. It is slow and cheap memory as compared to the primary memory. It has a large storage capacity than primary memory. Harddisk Drive is an example of secondary storage.

CPU(Central Processing Unit)

The CPU is the main unit inside the computer. The CPU is the brain of the computer system which does all the processing, calculations, problem-solving, and control operation of all the units in the computer.

The CPU consists of two units; Control Unit and Arithmetic and logical Unit

Control Unit:

It is known as the central nervous system of the computer system. This unit control all the function like input, processing, and output of the computer. It doesn't perform any processing on data. The Control Unit is able to maintain order and direct the operations of the entire system. 

Arithmetic and Logical Unit(ALU):

The ALU is the part where actual execution is done. All the calculations and comparisons are performed in ALU. This unit performs arithmetic functions like addition, subtraction, multiplication, division. It also does logical operations like greater than, less than, and equal to, etc.

Output Unit

Devices that are used to provide information to the user in the desired format are called output units. This unit is a link between the computer and the users. Monitor, printer, etc are output device that displays information to the user.

An output unit performs the following functions:

1) It accepts the results produced by the computer which are in coded form.

2) It converts these coded results to a human-readable form.

3) It supplied the converted results to the outside world.

Characteristics of Computer