Computer Hardware

What Is Computer Hardware ?

Computer Hardware

Computer Parts

Peripheral Devices

The computer hardware components are the physical parts of  the computer system .  The computer hardware includes the electronic , electrical  and mechanical components connected to the computer system .

The computer hardware components can be of two types . Some hardware components are placed inside the computer system case ( cabinet ) and the peripheral hardware devices are connected externally to the system.

In this article , you will learn the various computer hardware components , its functions and other important technical features which computer science students must know .

Computer Hardware Components

Table Of Contents

What is Computer System ?

Before we start the discussion on various hardware components , let us first understand the computer system architecture.

A computer system is an electronic device . The computer system is made up of  both software and hardware components .  The software and hardware components are essential part of every computer system.

The software components provide the set of program instructions necessary to drive and control the computer system. The computer makes use of two types of software components .

The system software is a type of software used by the system itself to drive the various hardware components connected to the computer system.

For example, the operating system is a type of system software which works as an interface between the user and the hardware components.

Computer System . How does a computer work
Computer System . How does a computer work

Whereas, the application software is specially designed to provide a specific functionality to the computer user . For example we use different types of application software to write the documents , emails or play music and video player to watch any video files.

A computer system basically performs four types of basic operations . These four types of operations include input operations , storage operations , data processing and output operations.

The computer system performs these operations with the help of various software and the hardware components during the program execution.

A computer system operations can be functionally grouped into four basic units . These four include input unit , memory unit , central processing unit and the output unit .

Computer System , system architecture

It is important to understand in detail the functions , different types and technical features of various hardware components and how these components interact with other components in a computer system.

What Is Computer Hardware ?

The computer hardware a general term used to describe the various physical components that are part of  the computer system .  

The hardware component could be either an electronic , electrical  and mechanical component used in the  computer system.

The computer system is a digital machine which makes use of different types of electronic hardware components.

These electronic components include motherboard , hard disk  , microprocessor , RAM modules , graphics card and other such electronic components.

Computer System Hardware Components

The computer system hardware also includes the electrical components such as power supply unit ( SMPS – Switch Mode Power Supply ) , heat sink for the processor , system ventilation and cooling fan and electrical cables used in the system.

The computer also needs some mechanical hardware components . These mechanical components include system case ( cabinet ) and different types of screws , clamps used to fix other devices.

What Is Computer Hardware ?

Types Of Computer Hardware

Based on the location of the computer hardware component , the hardware can either be connected internally or externally to the system. Two types of hardware components are internal and external components.

The components are said to be internal when they are installed inside the computer case. Whereas, it the hardware is connected externally then it is referred as external or peripheral device.

  1. Internal Hardware Components.
  2. External Hardware Components.

Internal Hardware Components

If the hardware component is placed and connected inside the computer system case ( cabinet ) then it is referred as system component or internal  system component .

The internal system hardware components include :

Internal Computer Parts

Computer System Hardware Components

Computer Motherboard

Computer System Hardware Components

What Is Computer Hardware ?

Peripheral Devices

External Hardware Components

Whereas , some computer hardware components are connected externally to the system . Such externally connected components are also commonly referred to as the peripheral hardware devices.

These externally connected devices are very much part of the system and the system will flash an error during the booting if some of these devices are not connected .These devices are connected to the system externally with the help of various connection cables.

For example , the externally connected hardware includes :

Input And Output Devices

The input and output devices are an essential feature of every computer system . The system will perform the necessary checks at the time of booting to ensure some of the essential devices are connected to the system .

For example , the standard input device such as keyboard and output device computer display monitor connection is checked during the system booting process .

Computer Input Devices
Computer Output Devices

Input Devices

The input devices are used to accept user data in terms of text , numbers , images or any other digital input. The commonly used input devices include keyboard , mouse , scanner , camera and other such input devices.

Output Devices

The output devices are used by the system to provide and present the processed data to the user . The most commonly used output devices include the display monitor , printer , plotter and external storage devices.

What Is Computer Hardware ?

Computer Hardware Explained

Let us now understand each of these devices in terms of the functions and the technical features  in detail.  

Computer Case

What Is Computer Case ?

The computer case ( also referred as cabinet or chassis ) is the most prominent visible component of the system which provides a safe house to some of the most important internal system components .

The computer case is usually made up of metallic parts . The size of the computer case depends upon the system configuration and the budget.

Computer Cabinet , Case
Computer Cabinet , Case

The main function of the system case is to provide a protected enclosure to organize and assemble various internal components such as motherboard , microprocessor ( CPU ) , main memory RAM , SMPS power supply unit , hard disk and other system devices.

Types Of Computer Case

The computer cases are available in different shapes , size and other technical features depending upon the system requirements.

The computer case types and the its form factor include Super Tower case ( EL – ATX , Height – 27 to 29 inches )  , Full Tower case ( EATX , Height – 22 to 27 inches )  ,  Mid Tower case ( ATX , Height – 17 to 21 inches ) ,  Mini Tower case ( Micro -ATX , Height – 22 to 27 inches )  , Small Case ( Mini –ITX  , Height – 10 to 12 inches )  , HTPC Case ( Mini –ITX  , Height – 4 to 6 inches ).

 The computer case selection also depends upon the motherboard form factor and other system specifications .

Computer Case Types , Computer Case Form Factor

Case Form Factor

What Is Computer Case Form Factor ?

In computer hardware industry the form factor for computer case indicates a standard size of the computer case that is compatible with specific type of motherboard. A motherboard is also categorized based on the form factor applicable for the motherboard size.   

Case Image

Case Name

Case Form Factor

Case Size

Super Tower


27 To 29 Inches

Full Tower


22 To 27 Inches

Mid Tower


17 To 21 Inches

Mini Tower

Mini - ATX

14 To 16 Inches

Small Case

Micro - ITX

10 To 12 Inches


Micro - ITX

4 To 6 Inches

What Is Computer Hardware ?

Computer Motherboard

The motherboard is the main printed circuit board ( PCB ) in a computer system . The motherboard works as a junction and connection board for some of the most important components used in a computer system.

The motherboard provides the connection sockets for the  microprocessor ( CPU ) , main memory RAM , secondary memory hard disk , graphics card and controller chips set which connects the various input and output devices to the system.

The motherboard selection depends upon the system specifications in terms of processor to be used , main memory RAM size required , expansion slots required and the intended purpose of the system .


What Is Motherboard ?

Computer Motherboard, what is motherboard


If you are building a PC , then always first select the processor brand ( Intel OR AMD ) and a specific processor which you intend to use and then select the  matching motherboard.

What Is Motherboard Form Factor ?

The motherboard is the main circuit board which connects all the system components together . The motherboard comes in different sizes as shape depending upon the requirements.

The motherboard form factor is referred to its size , shape , input & output panel and the mounting holes . The motherboard form factor is a uniform standard implemented by the motherboard manufacturing industry .

The motherboard form factor standards include AT ( discontinued ) ,  Extended ATX ( 12 X 12 inch size ) , ATX ( 12 X 9.6 inch size ) most common , Micro ATX ( 9.6 X 9.6 inch size )  , Mini ITX ( 6.7 X 6.7 inch size ).

Motherboard Form Factor


Central Processing Unit ( CPU )

The microprocessor is the brain of the computer and provides the real processing power to the system. It is also referred to as CPU ( Central Processing Unit )  or simply a processor .

The microprocessor chip is mounted inside a special socket provided on the motherboard . The  CPU socket can firmly hold the processor chip due its lever locking mechanism.

The CPU generates considerable heat and therefore , a special heatsink with miniature fan is placed on the top of the processor chip . This heatsink protects the processor chip from damage due to excessive heat.

What Is Central Processing Unit ( CPU )

The processor market is mainly controlled by two American companies that is Intel Corporation and  AMD . However , Intel is a clear market leader in the processor market .

 And therefore , the Intel processor needs compatible motherboard . Similarly , the AMD processor also needs a compatible motherboard to mount the AMD processor chip .

Processor Socket On the Motherboard

Processor Socket On Mother Board , Central Processing Unit

The processing power of the processor ( CPU ) is measured and expressed in terms of its speed to execute the program instructions.

The CPU is driven by a stream of clock pulses generated by the CPU clock . The frequency of the clock is called a clock rate, or the speed of the CPU.

The CPU speed is  measured in hertz ( Hz ). The modern processors speed is measured in Gigahertz ( GHz ) . One GHz is equal to 1,000,000,000 cycles per second.   


How CPU Works ?

What Is Computer Hardware ?

Power Supply Unit

Switch Mode Power Supply ( SMPS )

The power supply unit ( PSU ) is another important component mounted inside the computer cabinet ( Case ). The SMPS ( Switch Mode Power Supply ) is the most commonly used PSU .

The main function of the power supply unit ( PSU )  is to provide electrical power supply to the various components present inside the system cabinet such as motherboard , hard drive and other components as per their requirements.

The power supply requirement for the system depends upon the system configuration and the specifications in terms of  voltage and current requirements.

Power Supply Unit , SMPS
Power Supply Unit , SMPS

The system power supply requirements should be precisely calculated . The wrong calculation or under powered supply to the system can cause damage to some of the expensive components such as processor , motherboard or RAM modules.

The various system components have different power requirements and therefore, the SMPS provides multiple power supply wire connectors meant for different components.

Some reputed system cabinet brands provide inbuilt power supply unit and the system ventilation fan already pre installed.  

RAM Modules

Random Access Memory ( RAM )

The computer system memory unit consist of different types of memories organized in a hierarchical order with different size and speed. Each of these memory performs a specific role during the program execution.

The RAM ( Random Access Memory ) is the main memory ( primary memory ) and a critical resource  that is managed by the operating system.

The RAM is present in the system in the form of RAM modules mounted into RAM slots ( DIMM slots ) on the system motherboard. The RAM modules are also commonly  referred to as DIMM .

How To Install RM Modules On The Motherboard

The standard size of the RAM ranges between 4 GB to 16 GB which also depends upon the type of the operating system . The 32 Bit operating system can support maximum 4 GB RAM whereas 64 Bit operating system can support any size of the RAM.

As the hardware technology evolved , the RAM technology also changed over a period . The RAM generation technology started from DDR1 and DDR4 is the latest standard .

The RAM modules to be used in the  system must be compatible with the motherboard type. The RAM slot compatibility is checked  in terms of voltage , number of pins and the frequency of the RAM module.

Each motherboard supports a specific type of the RAM which is generally mentioned on the RAM slots present on the motherboard.


What Is Computer Memory ?

What Is Computer Hardware ?

Graphics Card

Graphics Card And Sound Card

The microprocessor ( CPU ) in a computer system is responsible to perform all the calculations necessary to render a quality image or play a video clip . The CPU inside a general purpose computer can efficiently handle the routine tasks without any problem.

However , sometimes  the computer is used for some high end jobs such as video editing , computer graphics or simply for playing any high end video games .

For handling  a such heavy duty applications , the CPU performance needs to be augmented with the help of graphics card . The graphics card is equipped with a dedicated processor called GPU ( Graphics Processing Unit )  that can efficiently handle the graphics.

Graphics Card
Graphics Card

A graphics card is a separate processing unit ( GPU ) installed on the motherboard into the PCI expansion slots which significantly improves the user experience and the quality of the graphics rendered by the system.

NVIDIA , AMD and Intel are some of the leading brands for Graphics card.

What Is Computer Hardware ?

Sound Card

Similarly , sometimes  the computer is used for some high end jobs such as video editing with sound effects , sound recording studio quality audio or for playing any high end music.

For handling  such heavy duty audio applications , the CPU performance needs to be augmented with the help of additional sound card . The sound card is equipped with a dedicated processor that can efficiently handle all the audio processing jobs.

Sound Card External
Sound Card Internal

The sound card is separate unit installed on the motherboard into the PCI expansion slots which significantly improves the system performance to handle the sound processing work .

The sound card also works as an interface which provides some additional functionality to attach various DJ equipments and also the musical instruments to the computer system.

The sound card can either be attached internally or connected externally .

What Is Computer Hardware ?

Hard Disk Drive

The Hard Drive ( Disk Memory ) is the permanent memory ( secondary memory ) and it is managed by the operating system.

The hard disk is fixed into a specific slot bay present in the system cabinet which holds the hard drive with the help of screws .

The hard disk is connected to the system using SATA cable for data transfer and the power connection from SMPS. However , the external hard disk can be connected through any USB port .

 The hard disk runs on a mechanical parts which consist of number of rotating discs and mechanical head to read and write the data. This makes it prone for failure after prolonged usage.

Internal Hard Drive Inside View
Internal Hard Drive

This technology is being replaced by SSD ( Solid State Drive ) drives. However , SSD are very expensive at the moment and therefore , the hard disk are still being extensively used.

Depending upon the storage requirements for the system , number of  disk drives can be added to the system into the internal bays of the system cabinet.

The hard disk drives are available in different capacities and types suitable for different applications.

Toshiba , HP , Western Digital  ( WD ) , Seagate , Sony  and Samsung are some of the leading reputed hard disk brands available in the market.

Internal Hard Drive

What Is Computer Hardware ?

Solid State Drive ( SSD )

The solid state drive ( SSD ) is a high speed permanent memory ( secondary memory ) and it is managed by the operating system. The solid state drive disk SSD can be fixed into a computer case in number of ways .

However, the most common place for SSD is to use one of the  specific slot ( internal bays )  present in the system case . The SSD disk is fixed into the internal bays which holds the SSD drive with the help of screws .

The main advantage of the SSD drive is the long life since there are no moving mechanical parts inside the SSD . Further, it has vary high data access speed which can significantly improve the computer performance.

How To Install SSD

The solid state drive ( SSD ) disk is connected to the system using SATA cable for the data transfer. The power supply is provided to SSD using one of the connector  from PSU SMPS.

The solid state drive ( SSD ) can also be connected to the system externally  through any USB port .

The solid state drive ( SSD ) does not have any moving mechanical parts which makes it a much better option as compared to hard disk drive. The SSD is made up of memory chips which gives a very high speed data access.

Hard Drive
Solid State Drive SSD

The SSD ( Solid State Drive ) drives are now being used as an alternative to the hard disk drives. However , the SSD are relatively far more expensive at the moment as compared to the hard disk drives .

The solid state drive ( SSD ) disks are available in different storage capacities . Kingston , Sandisk , Toshiba , HP , Intel ,Western Digital  ( WD ) , Seagate  and Samsung are some of the leading reputed SSD disk brands available in the market.


If you are building a PC and planning to use SSD for secondary storage then it is important to use the correct type of the SATA cable to get the full advantage of high speed data access . The wrong selection of the SATA cable can affect the data access speed of the SSD.

What Is Computer Hardware ?

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