What is computer network?

Admin

1 Dec, 2023

What is a computer network?

A Computer Network is a system in which many computers (such as desktops, laptops, smartphones, tablets, servers, etc. computing devices) connect with each other and exchange data and files.

All the devices in a computer network are connected to each other through wire or wireless media.

Every network consists of hardware and software that connects computers and tools to each other.

As I said above, a computer network is formed by connecting many computing devices to each other and these devices use some hardware and software components to connect with each other.

So let us now know about some hardware and software components used in computer networks.

Computer Network Components

Some of the main components that enable computers to communicate (exchange data) are as follows:

1) Hardware Components

Connecting devices - These are the middleware between the computer and the network that binds them together.

Some of the connecting devices that connect computers and networks are as follows –

Bridges
Routers
Gateways
Hubs
Switches
Repeaters

Servers - Servers are computers in which data and information are stored. These data and information are transferred from the server to the network.

Client - A client is a computer that is connected to other computers present in the network and can receive data sent by other computers.

Transmission Media - All the computers inside the network are connected to each other through some transmission medium (like optical fiber cables, coaxial cables, microwaves, infra-red waves etc.) which makes data transfer possible between them. is. It is also known as links, channels or lines.

Network interface card - All the computers in the computer network have a card which is called Network Interface card (NIC). It is hardware that helps the computer to connect with the network.

A Network Interface card (NIC) contains the MAC address of the computer, which is also called the physical address of the computer.

A Network Interface card (NIC) controls the data flow between the computer and the network. A NIC can send and receive data.

Access points - These allow devices to connect to the network without any cables.

2) Software Components

Networking Operating System - A Network Operating System is a program that usually runs inside the server. It allows computers to communicate through networks.

Protocol - Protocol are some rules and guidelines that every computer present in the network follows while sharing data and information so that proper communication can take place between those devices.

Some popular protocols are – IP, TCP, UDP, FTP etc.

Types of Computer Network

There are many types of computer networks which are used by different people and organizations for different purposes.

Computer networks can be divided into four main types on the basis of their size.

LAN (Local Area Network)
PAN (Personal Area Network)
MAN (Metropolitan Area Network)
WAN (Wide Area Network)

1) LAN (Local Area Network)

Local Area Network is an operator in a local area, it is formed by connecting two or more computers located in a small area. Local Area Networks are commonly used in homes, offices, schools.

Data transfer rate in local area network is very high. A local area network provides more security.

In a local area network, devices are connected through wired or wireless means. But in most local area networks, computers are connected via Ethernet cables, which are much less expensive.

Advantages of LAN

Resource Sharing: LANs allow for the sharing of resources such as printers, files, and applications among connected devices, which can improve efficiency and reduce costs.
High-Speed Data Transfer: LANs offer high-speed data transfer within a local area, making it efficient for internal communication and resource sharing.
Centralized Data Management: LANs enable centralized data management, making it easier to back up and secure data.
Reliability: LANs are generally more reliable than wide area networks (WANs) because they are confined to a smaller geographic area.
Cost-Effective: LAN components are affordable, making LANs cost-effective for small to medium-sized businesses.

Disadvantages of LAN

Limited Coverage: LANs are limited in coverage and are not suitable for connecting geographically dispersed locations.
Maintenance and Administration: LANs require constant administration by experienced engineers for functioning, which can be costly and time-consuming.
Isolated Networks: LANs are isolated networks, which limits connectivity to devices within the same LAN.
Complex Expansion: Expanding LAN can be complex, especially in large organizations, and may require network redesign.
Single Point of Failure: LANs typically have a single point of failure, such as a central server. If this server fails, the entire network can go down.

2) PAN (Personal Area Network)

A personal area network is organized around a person. The range of which is usually in the range of 10 meters.

This network is generally used by a person to connect computer equipment and devices for personal use, hence it is known as Personal Area Network.

Thomas Zimmerman was the first to use a personal area network to connect his devices.

Through personal area network we can connect our computer, mobile, headphones etc.

For example – when you connect your mobile to a computer through a cable, it is called a Personal Area Network.

In a personal area network, devices can be connected to each other through both wired and wireless methods, such as sometimes you have connected your mobile and your friends' mobiles via Bluetooth or Wi-Fi, this is an example of a wireless personal. Area network. In which devices are connected to each other through wireless media.

Advantages of PAN

No Extra Space Required: PAN does not require extra space or wires. For connecting two devices, you only need to enable Bluetooth in both devices to start sharing data among them.
Connect to Many Devices at a Time: Many devices can be connected to one device at the same time in a personal area network. You can connect one mobile to many other mobiles or tablets to share files.
Cost-Effective: No extra wires are needed in this type of network, making it more cost-effective than conventional networks.
Easy to Use: It is easy to use, and no advanced setup is required. Moreover, it is simple to maintain, since there are no cables, servers, or routers involved.
Reliable and Secure: PAN is a reliable and secure network because all the devices are authorized before data sharing. Third-party injection and data hacking are not possible in PAN.

Disadvantages of PAN

Limited Range: PAN has a limited range of only 10 meters, which can be a disadvantage if you need to connect devices that are farther apart.
Slow Data Transfer: PAN has a slower data transfer rate compared to LAN and WAN networks.
Infrared Signals Travel in a Straight Line: Infrared signals used by some devices in PAN travel in a straight line, which can be a disadvantage if the devices are not in a direct line of sight.
Interference with Radio Signals: PAN interfaces with radio signals, which can cause interference with other devices that use radio signals.
Devices are Not Compatible with Each Other: Some devices may not be compatible with each other, which can cause issues when trying to connect them in a PAN.

3) MAN (Metropolitan Area Network)

Metropolitan Area Network is a high-speed network that covers a very large geographical area.

It is a set of LANs connected by routers and local telephone exchange lines, which can be operated by a private company or a local telecom company.

The most commonly used protocols in MAN are RS-232, Frame Relay, ATM, ISDN, OC-3, ADSL, etc.

MAN covers an area smaller than WAN and larger than LAN. Its range is 5 to 50 kilometers.

Uses of MAN

It is used for communication between banks located in a city.
It can be used in airline reservations.
It can be used in a college located within a city.
Also used to connect connected fire stations in a city.
Used for communication between connected branches of a school in a city.

Advantages of MAN

Cost-effective Sharing of Resources: MAN allows for cost-effective sharing of common resources such as printers, software programs, and files among distributed workstations or users.
Centralized Management: Like LAN and WAN, MAN also offers centralized management of data and files, making it easier to monitor and control network traffic.
Higher Security: MAN provides more security compared to WAN and is easier to implement.
Fast Interfacing: MAN helps people interface fast LANs together, due to the easy implementation of links.
Larger and Controllable Network: MAN utilizes the drawbacks of both LAN and WAN to provide a larger and controllable computer network.

Disadvantages of MAN

Difficult to Manage: Once a MAN becomes large, it can be difficult to manage the network.
Security Risks: It is difficult to make the system secure from hackers and industrial espionage.
Higher Installation and Management Costs: Network installation requires skilled technicians and network administrators, which increases overall installation and management costs.
More Cables Required: It requires more cables for connection from one place to the other compared to LAN.
Slower Data Transfer Speed: The data rate is slower in a MAN compared to LAN.

4) WAN (Wide Area Network)

WAN is a network spread over a very large geographical area, which is similar to MAN but it covers a larger area than MAN. Its range is more than 50 km. It is used to connect the networks of many countries, for companies and banks to communicate with their branches and customers, etc.

Internet is the largest WAN in the world. Computers are connected to WAN through public networks such as telephone systems, leased lines and satellite.

Exampls of WAN

stock exchange network
Railway Reservation System
satellite system

Advantages of WAN

Greater Geographic Coverage: WANs are designed to cover large geographic areas, connecting multiple LANs and other networks together.
Enhanced Data Security: WANs provide enhanced security protocols to protect data as it travels, making them much more secure than the internet itself.
Improved Collaboration: WANs enable better collaboration among employees working in different locations, allowing them to share resources and applications.
Better Access to Resources: WANs provide users with better access to resources, as they can share software files and other resources among distributed workstations or users.

Disadvantages of WAN

Slower Speeds: WANs are slower compared to Local Area Networks (LANs) due to the larger distance and the need to transmit data over longer distances.
Security Risks: WANs are more vulnerable to security risks, such as hacking, viruses, and malware, due to the larger area and the difficulty in securing every point of connection.
Distance Limitations: WANs are limited by distance, and the farther the connection, the slower the data transfer speed, which can affect the quality of communication.
Higher Costs: WANs have higher initial investment costs compared to LANs, and maintaining the network can be difficult and costly.
Dependency on Service Providers: WANs are often provided by third-party service providers, and this can create dependency issues. If the service provider experiences any issues or disruptions, it can affect the operation of WAN, and this can cause disruptions to businesses and organizations.

What is computer network?

What is a computer network?