• A computer network is a group of computers linked to each other that enables the computer to communicate with another computer and share their resources, data, and applications.
• A computer network can be categorized by their size.
• A computer network is a group of computers linked to each other that enables the computer to communicate with another computer and share their resources, data, and applications.

A computer network can be categorized by their size.

1. Local Area Network (LAN)
2. Metropolitan Area Network (MAN)
3. Wide area network (WAN)

Local Area Network (LAN)

• Local Area Network is a group of computers connected to each other in a small area such as building, office.
• LAN is used for connecting two or more personal computers through a communication medium such as twisted pair, etc.
• It is less costly as it is built with inexpensive hardware such as hubs, network adapters, and Ethernet cables.
• The data is transferred at an extremely faster rate in Local Area Network.
• Local Area Network provides higher security.

Metropolitan Area Network (MAN)

• MAN network covers larger area by connections LANs to a larger network of computers.
• In MAN various Local area networks are connected with each other through telephone lines.
• The size of the Metropolitan area network is larger than LANs and smaller than WANs (wide area networks), a MANs covers the larger area of a city or town.

Wide Area Network (WAN)

• A Wide Area Network is a network that extends over a large geographical area such as states or countries.
• A Wide Area Network is quite bigger network than the MAN.
• A Wide Area Network is not limited to a single location, but it spans over a large geographical area through a telephone line, fiber optic cable or satellite links.
• The internet is one of the biggest WAN in the world.
• A Wide Area Network is widely used in the field of Business, government, and education.

Advantages of Wide area network (WAN)

• Geographical area: A WAN provides a large geographical area. Suppose if the branch of our office is in a different city then we can connect with them through WAN.
• Centralized data: In case of WAN network, data is centralized. Therefore, we do not need to buy the emails, files or back up servers.
• Get updated files: Software companies work on the live server. Therefore, the programmers get the updated files within seconds.
• Exchange messages: In a WAN network, messages are transmitted fast. The web application like Facebook, Whatsapp, Skype etc.
• Sharing of software and resources: In WAN network, we can share the software and other resources like a hard drive, RAM.
• Global Business: We can do the business over the internet globally.
• High bandwidth: The high bandwidth increases the data transfer rate which in turn increases the productivity

Disadvantages of Wide area network (WAN)

• Security issue: A WAN network has more security issues as compared to LAN and MAN network as all the technologies are combined together that creates the security problem.
• Needs Firewall & antivirus software: The data is transferred on the internet which can be changed or hacked by the hackers, so the firewall needs to be used. Some people can inject the virus in our system so antivirus is needed to protect from such a virus.
• High Setup cost: An installation cost of the WAN network is high as it involves the purchasing of routers, switches.
• Troubleshooting problems: It covers a large area so fixing the problem is difficult.