What is Computer Hardware

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What is Computer Hardware A 2 Z?

computer is made up of many devices which are called computer hardware and we cannot consider any one device as a computer,

Some of the major computer hardware are as follows: –

  • Processor,
  • Memory / Storage devices,
  • Input output devices,
  • Motherboard


So in this way we can say that all the devices working in the computer that we can touch, which can break and which can be changed when broken, are called computer hardware.

There are many types of computer hardware and as technology is getting advance computer hardware is also becoming advance and cheap.

Whatever software is installed in the computer, they all are installed inside the hardware and no computer software can work without computer hardware, thus we can say that computer software and computer hardware are complementary to each other & are able to work with each other

Type of Computer Hardware

Central processing unit

this is also called Processor or cpu, cpu is the brain of a computer, just as a man takes all his decisions with his mind, similarly the computer makes all its decisions through cpu

cpu has 2 parts

  • Arithmetic Logic Unit (ALU),
  • Control Unit (CU)

Arithmetic Logic Unit (ALU): –

ALU is the place inside the computer where instruction are executed,

All calculations and comparisons in the computer are done in ALU

Whatever data / instruction is kept in primary memory is transferred to ALU for processing and the intermediate result, generated by ALU, is temporarily sent to primary memory (RAM) and when that intermediate result is required by another process, then that is taken again in ALU.

In this way, when all data / instruction is completely executed by ALU, the final result is sent to primary memory (RAM).

Control unit: –

The entire computer system is controlled by the control system,

The control unit takes instructions from the program lying in the RAM and interprets them and then generates the signal according to the interpretation according to which the entire computer system works.


Motherboard is a very important device in computer hardware, just like the eyes, teeth, ears, nose, hands, feet are all engaged in our body and are operated by different nerves related to the brain, just like all the main computers hardware such as processor, input output devices, memory devices (storage devices) are connected to the motherboard and do their work interactively.

We also know motherboard as system board, main board, main circuit board and it is also known as logic board in smart phones.

What is motherboard?

(a type of computer hardware used for connecting all devices to each other)

The motherboard is one of the most important devices of the computer. Through motherboard all other important devices of the computer like CPU, RAM, HDD, Monitor, Mouse, Keyboard, USB devices etc are connected with the help of Dedicated Ports.

These dedicated ports are of many types such as power connector, processor socket, memory slot, video card slot, Ethernet port, expansion slot, keyboard port, mouse port etc.

All the important devices of the computer get power supply only with the help of the motherboard and all these devices communicate with each other and take data, information.

All the internal components of the computer (which are inside the cabinet) and all the external devices (which are outside the cabinet) connect with the help of the motherboard.

The motherboard itself is also called the “Printed Circuit Board”.

In a way, we can say that all the devices in the computer interact & share the data – information direct or indirect with each other with the help of motherboard

Input device (a type of computer hardware used for entering data into computer)

All of the devices of the computers by which any data, information,

are sent inside the computer by the user or through a device then these devices are called Input device.

It is that part of computer hardware that only gives data, information, instructions to the computer, it does not take from the computer.

There are many types of input devices (types of input devices)


  • keyword
  • mouse
  • mice
  • scanner
  • sensor etc

Output device (a type of computer hardware used for outputting data from computer)

All of the devices of the computers by which any data, information,

is received by a user then all those devices, through which data, information is coming out from the computer, are called Output device.

It is that part of computer hardware that only extracts data, information, instructions from the computer, but never enter it inside the computer.

There are many types of output devices (types of output devices)


  • Monitor
  • Printer
  • Sound Boxes
  • Projector etc

Memory / Storage Devices

In computer hardware, memory is used to store data, information, intermediate result and final result.

We know that there is a memory 2 category in a computer.

  1. Primary Memory
  2. Secondary memory

(What is Primary Memory & Secondary memory)

Primary memory is also called main memory or internal memory, it is directly connected to the CPU, it is faster than secondary memory but slower than CPU register.

(cpu register is also a type of memory but it is considered part of cpu / processor and its speed is the highest in all memory)

The storage capacity of Primary memory is less than Secondary memory.

There are 2 types of primary memory. RAM and ROM fall under the category of primary memory and Hard Disk Drive, Memory Cards, Pen Drives etc. come in the category of Secondary memory.

RAM – Volatile Memory

ROM – Non Volatile Memory

HARD DISK DRIVE – Non Volatile Memory

(Volatile memory and Non Volatile memory,

A volatile memory is one in which the data remains only as long as the volatile memory continues to receive power, hence this memory is also called a temporary memory while the data lying in the non volatile memory always remains whether this memory gets power or not. That is why Non Volatile memory is also called permanent memory)


RANDOM ACCESS MEMORY (RAM) is volatile memory, it is a memory in which data / information remains as long as it gets power supply. As soon as the power supply of memory is closed, all the data in this type of memory gets erased.

The processor in the computer performs all its work in RANDOM ACCESS MEMORY (RAM),

Once the size of RANDOM ACCESS MEMORY (RAM) was in Megabyte (MB) but today it is in Gigabyte (GB) size.

It is called Random Access Memory because it takes equal time to reach any part of it. It has both read and write operations.

What is RAM?

The full form of RAM is “Random Access Memory”, since RAM is volatile memory so it is also called temporary memory.

And the data that is stored in it is temporary storage of the data and the data remains in the RAM as long as the computer is on and the RAM keeps getting the power supply.

As soon as Computer Off, the data in RAM becomes erase and after that the data cannot be received. RAM is used in desktop computers, laptop computers as well as all smartphones today.

The main role of RAM is in decreasing or increasing the speed of a device, if the RAM is large then the speed of the device is high and if the RAM is small then the speed of the device also decreases.

Whatever files, audio, video, document etc. we open in computer laptop or mobile, they all open in RAM and the processor of the computer does all its work in this RAM only.

Types of RAM – How many types of RAM are there?

There are 2 types of RAM

  1. Static RAM
  2. Dynamic RAM

What is static RAM? 

The data in static RAM remains constant so there is no need to refresh it again and again.

SRAM requires more Chips than DRAM to store data of the same size, so SRAM costs more money than DRAM to build, SRAM is used as Cache Memory,

The speed of SRAM is higher than DRAM but less than the speed of Internal Registers of Processor.

(Data from RAM goes to cache memory and from cache memory to internal registers where the processor processes or executes the data).

What is Dynamic RAM? 

The data lying in dynamic RAM keeps changing, so it needs to be refreshed again and again. Dynamic RAM refresh thousand times in a second,

DRAM requires less Chips than SRAM to store data of the same size, so DRAM costs less to make than SRAM, this is the same RAM used in most devices.

Read Only Memory (ROM)

This ROM is called because it only has read, operation. The data lying in it is inserted at the time of its creation. The ROM contains the necessary instructions that the computer may need at any time. This is non-volatile memory,

ie data / information is not destroyed even when there is no electricity. There are many types of ROMs such as: –






Secondary memory includes Hard Disk Drive, Memory Cards, Pen Drives etc., we use Secondary memory when the data to be stored is very high and / or that data will be required in future also.

Some of the major secondary memory are as follows: –

Hard Disk Drive

Hard disk drive in the computer is an example of non volatile memory

and in it the data, information is kept, which we may need in future also.

Hard Disk Drive is the largest data storage device in a computer.

All system software installed in computer such as operating system, device drivers and all application software and all software related to computer remain in Hard Disk Drive.

Hard Disk Drive is also called HD or HDD.

Hard Disk Drive is a Non Volatile Memory device, therefore users can store and retrieve their data, information permanently in it.

All computers, laptops, palmtops have Hard Disk Drive.

computer hardware a 2 z


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