Computer Hardware

Computer hardware refers to the physical components of a computer that you can see and touch. These components work together to process input and deliver output based on user instructions. In this article, we’ll explore the different types of computer hardware, their functions, and how they interact to make your computer work.

The computer has mainly has two major components:

1. Hardware
2. Software

In this article, we only discuss computer hardware.

What is a Computer Hardware

Computer hardware is a physical device of computers that we can see and touch. E.g. Monitor, Central Processing Unit, Mouse, Joystick, etc. Using these devices, we can control computer operations like input and output.

Also read, Peripheral Device

Computer Hardware Parts

These hardware components are further divided into the following categories, which are:

• Input Devices
• Output Devices
• Storage Devices
• Hardware Components

Input Devices

Input devices allow users to interact with a computer by entering data or commands. These devices convert the input into a format that the computer can process.

Now we discuss some input devices:

• Keyboard: The most widely used input device, featuring 104 keys, including alphabetic, numeric, and function keys. Modern keyboards connect via Bluetooth, replacing traditional wired connections.
• Mouse: A pointing device that controls the cursor on the screen. It features left, right, and middle buttons for selection and interaction. The sensor inside the mouse detects its movement speed, adjusting the cursor accordingly.
• Scanner: Scans documents, images, and other media, converting them into digital formats for editing or processing, similar to a Xerox machine.
• Trackball: A stationary pointing device with a ball that the user rotates to control the cursor, requiring less space than a traditional mouse.
• Light Pen: A light-sensitive pen used to draw or select objects on a CRT screen by detecting raster patterns, offering a direct interaction with the display.
• Microphone: Converts sound into electrical signals. It captures voice input for speech recognition and voice commands on the computer.
• Optical Character Reader (OCR): Scans printed or handwritten text, converting it into digital data by detecting reflected light from the characters, similar to a scanner.
• Bar Code Reader: Reads bar codes and converts them into digital data for processing. The bar code consists of light and dark lines that encode information.

Output Devices

Output devices display the results of tasks given to the computer in a human-readable form. Let’s discuss some common output devices:

• Monitor: The main output device. It is also called VDU(visual display unit) and it looks like a TV screen. The Monitor displays the information from the computer. It is used to display text, video, images, etc.
• Printer: A printer is an output device that transfers data from the computer in a printed format by using text or images on paper. There are both coloured and black & white printers. Further, there are also different types of printers, like Laser Printer, Dot-matrix printers, and Inkjet printers.
• Plotter: It is similar to a printer but potters are large. A plotter is used to generate large drawings, architectural blueprints, etc. on paper and these are high-quality images and drawings and large.
• Speakers: It is a very common output device and it gives sound as an output. The speaker is generally used to play music or anything having sound.

Storage Devices

Some devices are used for storage purposes and are known as secondary storage devices. Some of them are discussed below:

1. CD (Compact disc): A CD is circular and made up of thin platted glass and plastic polycarbonate material. It has a storage capacity of 600 MB to 700 MB of data. It has a standard size of 12 cm with a hole in the centre of about 1.5 cm and 1.2 mm in thickness. There are 3 types of CDs, which are:

• CD-ROM (CD - Read Only Memory): Contents of this type of CD cannot be erased by the user. Only the publisher is allowed to access the data imprinted on this CD. CD-ROM is used for commercial purposes like for a music album or any application package by a software company.
• CD-R (CD-Recordable): In this, content or data can be stored once. After that, they can be read many times but the data or content cannot be rewritten or erased. (Kind of one-time use)
• CD-RW(CD-Rewritable): As the name suggests, this type of CD is used to rewrite the content or erase previous content and again write new content many times.

2. DVD (Digital Video/Versatile Disc): A DVD is the same as a CD but with some more features. A DVD comes in single and dual-layer formats. It has much greater storage capacity in comparison to CD. The storage capacity of a DVD with a one-sided single layer is - 4.7 GB, one-sided double layer - 8.5 GB, double-sided single layer - 9.4 GB, and double-sided double layer - 17 GB. There are also some types of DVDs, which are :

• DVD-ROM: In this type, the contents of the DVD cannot be written on or erased by the user. DVD ROM is used for applications and databases for distributing them in large amounts.
• DVD-R / DVD+R: DVD-R (DVD minus R) and DVD+R (DVD plus R) are two different kinds of discs and they are once recordableformatst. Also, they have no difference virtually.
• DVD-RW / DVD+RW: This is a kind of rewritable disc and it allows up to 1,000 rewrites.
• DVD-RAM: DVD RAM is accessed like a hard disk. It provides high data security and storage capacity. This is a kind of rewritable disc and it allows up to 1,00,000 rewrites.

3. Hard DiskAtheAn hard disk is a non-volatile storage device that uses its read/write heads to store digital data on the magnetic surface of a rigid plate. It is generally 3.5 inches in size for desktops and 2.5 inches in size for laptops. A hard disk can be classified further into 3 types, which are:

• Internal Hard Disk: It has a common storage capacity stated as GB or TB. A system case or cabinet is the place where it is located. It can perform faster operations and its storage is fixed. It is mainly used to store large data files and programs.
• Internal Cartridges: The Internal hard disk can't be removed from the system cabinet easily. To resolve this problem Internal Cartridges are introduced. So, Internal cartridges make it easy to remove CDs. It has a storage capacity of 2 GB to 160 GB. It is used as an alternative to an internal hard disk.
• Hard Disk Packs are used by organizations such as banks and government sector organizations to store large amounts of data. They have a storage capacity of PB (peta bytes).

Also read,

• What is RAM?
• What is ROM?

Hardware Components

Some important hardware devices known as the internal components are discussed below: 

1. CPU (Central Processing Unit)

The CPU is also known as the heart of the computer. It consists of three units, generally known as the control unit, the Arithmetic Logical Unit (ALU), and the memory unit. Below is the block diagram of the CPU is given:

As shown in the diagram input is given to the CPU through input devices. This input goes to memory and the control unit gets instructions from memory. The control unit now decides what to do with the input or instructions and transfers it to ALU. Now, ALU performs various operations like addition, subtraction, multiplication, division, logical operations, etc. After that, the final result gets stored in memory and finally passed to output devices to give the output. So, this is how the CPU works.

2. Motherboard

It is the main circuit board inside a computer and it contains most of the electronic components together. All the components of the computer are directly or indirectly connected to the motherboard. It includes RAM slots, controllers, system chipsets, etc. 

3. RAM (Random Access Memory)

It is also known as temporary or volatile memory. It holds the program and data, which are currently in process or processing. All the data is erased as soon as the computer is turned off or in case of a power failure. Data stored in this memory can be changed. There are two types of RAM:-

1. SRAM (Static RAM): SRAM consists of a flip-flop using a transistor or Mosfet (MOS). It is fast and has less access time. In this refreshing circuits are not required. But it is costly and requires more space. E.g. cache memory.
2. DRAM (Dynamic RAM): DRAM consists of capacitors and the data is stored in the form of capacitors. Capacitors charge when data is 1 and don't charge if data is 0. It requires refreshing circuits, as leakage of current in the capacitor can occur, so they need to be refreshed to the data. It is slower and has a higher access time. It is cheaper in comparison with SRAM. E.g. Main memory.

4. Video Graphics Array Port

A video input commonly used on computer monitors is called a video graphics array (VGA) port. Verifying that there isn't a loose connection, a damaged cable, or a broken display is one step in troubleshooting a VGA port. Compressed air can also be sprayed inside the VGA port by a computer expert to make sure it's dust-free.

5. Power Supply

All of a computer system's parts are powered by a power source. Typically, a power cord is used to connect a computer tower to an electrical outlet. By turning off the computer, unplugging and separating the power supply cord, or trying a different cord or socket, a technician can diagnose the power supply.

6. Cooling Fan

A computer's system to prevent overheating uses cooling fans. To aid customers who use their computers intensively, such as when streaming video or playing games, many computers contain more than one cooling fan. If a user detects their computer overheating, a computer expert might need to repair the cooling fan. The blades may be examined for any damage and cleared of any foreign objects. A technician's standard method of troubleshooting may involve replacing computer fans.

7. Hard Drive

On a computer system, files, programs, and other types of information are stored on hard drives, which are data storage devices. They utilise hard drives, which are magnetically coated discs used to store digital versions of information. A computer technician can suspect a corrupt hard disk when a hard drive dies.

Relationship Between Computer Hardware and Software