What is the Role of CPU in Computer System?| How CPU works?

Hey, guys today we are going to discuss the role of CPU in computer systems. So, let’s started…

CPU(Central Processing Unit)

The ALU(Arithmetic and logic unit) and the CU(Contol Unit) of a computer system are jointly together to make the Central Processing Unit.

The term CPU relates to a specific chip or the processor Which may be considered as the brain of the computer, where almost all the work of the computer is done with the help of the CPU. It is the main processor of the computer that carries out all the important functions of a computer system and also processed all the programs and instructions received by both software and hardware accordingly.

In the Modern computer, the CPUs are implemented on IC’s(Integrated Circuit), Which is known as “Microprocessor”. It is built with One or More CPUs on a Single MOS IC Chip (Metal Oxide Semiconductor Integrated circuit chips).

The first CPU was invented by an Italian physicist “Federico Faggin”. He invented the first commercial CPU in 1971 with the name of intel 4004.

In the CPU, there are three components:

  • Control Unit(CU)
  • Arithmetic and Logic Unit(ALU)
  • Memory Unit(MU)

Also, read the article “Components of CPU” to know more about these components.

Role of CPU In Computer System

The main role of the CPU is to process all the data such as calculating the difficult task in seconds, executing the instructions, Searching for data and Whatever we use in the computer like browsing, playing games, running software, etc., all this work is done by CPU.

So, now let’s see in detail how the CPU Performs its tasks.

The CPU has a complex IC’s Chip that has millions of transistors. As you know that the CPU is classified into three major parts are CU(Control Unit), ALU(Arithmetic And Logic), and MU(Memory Unit). The CPU chips are interfaced with the other components of the computers through the system bus, So there are three types of system bus are Control Bus, Data Bus, and Address Bus.

  1. Control bus – A Control Bus is the part of system bus that is used by CPU to communicate with other devices within a computer, It is known as Control bus. In other word’s the Control Bus is like a middleman which helps the CPU to communicate with other pheripheral devices.
  2. Data Bus – In computer architecture, the Data Bus is allows for the transferring data between different components to other components. It is known as Data Bus.
  3. Address Buss – It is also the part of system bus that is used to transfer the data between devices. Those devices are identified with the help of hardware address of the physical memory and then address it is stored in the form of binary numbers to enable the data bus to access memory storage. It is known as address bus.

How CPU Perfomed their Task

At the time of executing data, the CPU performs the tasks which we give the instruction to the CPU like open the folders, open the browser, play the video, open the terminal, etc. these all things are the instruction provides to the CPU to perform these tasks for users. There are some arithmetic operations like Addition, Subtraction, Multiplication, and division, etc. These are the algorithm which helps the CPU to fully able to perform their tasks. Without an algorithm, the CPU is nothing to do anything.

How the CPU Use Memory

As you know that there are two types of memory: 1.) Primary Memory (E.g. RAM, ROM, PROM, EPROM, etc,) 2.) Secondary Memory (E.g. Hard disk, Floppy disk, Magnetic tapes, etc.).

(Note: The Memory is not the part of CPU, they both are different)

The CPU heavily depends on the system memory because the CPU required storage for executing the data. It’s a normal thing When there is no storage, then where will we keep the data? there is no option to executing the files without storage. so the final conclusion is the storge is mandatory for execution.

The Primary memory/Main memory is temporary storage where it holds the instruction and data for a program while the program is executing. on the other hand, secondary storage is the permanent storage for storing the data by HDD/SSD, Floppy disk, and many other.

The control unit played an important role in using the memory because it is responsible to move the data/instructions from secondary into main memory.


So, Today I have told you the role of the CPU in a computer system. I hope you liked it, If is not then tell me in the comment why so that I will improve it as soon as possible.

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