Main Components of a Computer System

A computer is a sophisticated device that combines a large number of components. You may run a computer without some parts such as the Bluetooth, floppy disk drive, etc. But you cannot do it without the motherboard, RAM, Power Supply, Operating System, etc. things. They are the main components of a computer system.

The components of a computer system can be divided into two segments, which are software components and hardware components. In our today’s article, we will discuss both types of components. Keep reading the article to know about the main components of a computer system in brief.

Main Components of a Computer System

1. Input Unit

The input unit is one of the most fundamental components of the computer system. You may already know that the computer has self-intelligence, and it cannot perform any task with instructions from the computer. The input unit of the computer system lets the user enter or input commands and data for various types of functions. The input data can be in multiple forms, including words, numbers, commands, and actions.

The input unit is a must to give direct command and data to the computer. Later, the computer system utilizes the central processor units or CPU to process the data and provide consistent output. The mouse can be an example of the input unit, which is used to give direction and graphical commands to a computer. Besides, the keyboard is used to enter the data and text instructions to the device.

The touchpad is another vastly used input unit that is often used in different computer systems like ATMs, smartphones, laptops, and others. Some other examples of the input device can be the scanner, digital camera, microphone, joystick, barcode readers, Optical character reader, Magnetic Ink character readers, etc. 

2. Output Unit

The output unit functionalities are in reverse when compared with the input unit. As the name suggests, the output unit shows the output depending on the given input. After the central process unit processes the data, it needed to be converted into a human-readable form. That is because the language of the computer numbers and it produces outputs on its own language. A normal human being will never understand it. The output unit converts them into readable text or data and shows the output.

One of the examples of the output unit can be the display; we can see the output based on our input through this. More so, printers and speakers can print a document or play audio as output based on the given information by a user. Some other examples of the output device can be the headphone, video cards, sound cards, plotters, projectors, visual display units, etc.

3. Central Processing Unit (CPU)

The central processor unit is one of the most essential and integral parts of a computer system. As the name suggests, it processes the data based on the action provided by the user. When a user submits a command to the computer system, it starts processing the data, and the central processing unit or CPU does the whole procedure. There are also some components under the CPU, which we will discuss below.

a. Arithmetic and Logic Unit (ALU)

Arithmetic Logic Unit is shortly known as ALU, is a part of the Arithmetic Logic Unit of a computer system. The function of the section is to perform some necessary calculations like addition, subtraction, division, multiplication, and others. Apart from the calculations, the ALU can also perform some logical functions as the data comparison. 

b. Storage Unit

As soon as you enter data through the input device, the information is being stored in the memory unit of ALU for further processing. The data will stay in the Memory unit until different components of the CPU become ready to process the data. Typically, the memory unit does not require any instructions from the user as there are pre-programmed instructions for the data transmission.

RAM or Random Access Memory can be an example of the memory unit. It is a volatile memory, and the data in RAM disappear as soon as the power is lost.

c. Control Unit

The control unit is one of the most crucial parts of the CPU, and it is sometimes considered as the backbone of the computer system. After the user input data, it wants the input unit, and then the control unit sends the data to the right processing units based on the nature of data. More so, the control unit transmits the processed data to the relevant output unit for the user.

Main Hardware Components of a Computer System

A computer is basically a combination of a large number of hardware components. Check out the essential hardware components details below.


The name “Motherboard” says it all – the motherboard is the primary circuit inside the computer, which connects all the required hardware components. It is connected with the CPU, drives, memory slots, and the other peripherals. It provides the electric connection the components for the communication between them. It is also the place where the microprocessor’s chipset stays to provide a suitable interface for CPU and buses. The motherboard of the computer is sometimes considered as the heart of the entire system.


Ram or Random Access Memory is another crucial part of the computer system. It is storage components that temporarily store the commands, files, or instructions. RAM is vital because the speed of a computer system mostly depends on it, along with the CPU. A computer with larger RAM and lower CPU can run better when compared with low RAM and minimal CPU computer system. RAM can be separately added in both desktop and laptop computer systems.

Video Card

The video card is another essential hardware component that shows you images or visual representation on the computer monitor. It also assists in rendering the images on the screen and also ensures clarity and details of the pictures. The component is highly crucial for these who work with graphics as well as play high-end computer games. 

Power Supply Unit

The PSU or Power Supply Unit is the component of the computer that supplies the required electricity for the operation. However, the primary function of the power supply is to convert the High AC voltage to safe voltage to prevent any risk. You simply cannot power up a computer system without using a power supply. 

HDD storage

The hard drive is another vital part of the computer that allows you to save or store the data and files for a long time. Unlike the RAM, the data in the hard drive stays even when you turn off the PC. The operating system of the computer is also stored in the hard drive, along with the program files and other crucial data. You can also save the media files, games, documents, photos, etc. on the hard drive storage. Sometimes when the RAMs run out of memory, the hard drive is used by the computer as a virtual memory bank.

Though the computer systems come in different types and shapes, the primary or main components can be found in all of them.  You cannot be even thought of a computer system without the main components like operating system, motherboards, power supply, etc.

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