What is a Computer Network? Definition, Types, and Examples

What is a Computer Network?

A computer network is multiple computers connected together using a telecommunication system for the purpose of communicating and sharing resources. A computer network may be described as the interconnection of two or more computers that may share files and folders, applications, or resources like printers, scanners, webcams, etc. The Internet is also a type of computer network that connects all the computers of the world that have Internet facility on them.

A Simple computer network may be constructed from two computers by adding a network adapter (Network Interface Controller [NIC]) to each computer and then connecting them together with a special cable called a crossover cable. This type of network is useful for transferring information between two computers that are not normally connected to each other by a permanent network connection or for basic home networking applications.

Types of Computer Networks
Below is a list of the most common types of computer networks.

1. Personal Area Network (PAN)
   A personal area network (PAN) is a computer network used for communication among computer devices (including telephones and personal digital assistants) close to one person. The reach of a PAN is typically a few meters. PANs can be used for communication among the personal devices themselves or for connecting to a higher-level network and the Internet.
   Personal area networks may be wired with computer buses, such as USB. A wireless personal area network (WPAN) can also be made possible with network technologies such as IrDA and Bluetooth.

2. Local Area Network (LAN)
A network that is limited to a relatively small spatial area, such as a room, a single building, is called a local area network. Local area networks are sometimes called a single-location network.
For administrative purposes, large LANs are generally divided into smaller logical segments called workgroups. A workgroup is a group of computers that share a common set of resources within a LAN.

3. Metropolitan Area Network (MAN)
A network that connects two or more Local Area Networks together but does not extend beyond the boundaries of the immediate town, city, or metropolitan area is a metropolitan area network. Multiple routers, switches & hubs are connected to create a MAN.

4. Wide Area Network (WAN)
A WAN is a data communications network that covers a relatively broad geographic area and that often uses transmission facilities provided by common carriers, such as telephone companies.

1. Speed: Sharing and transferring files within Networks is very rapid. Thus saving time, while maintaining the integrity of the file.
2. Cost: Individually licensed copies of many popular software programs can be costly. Networkable versions are available at considerable savings. Shared programs, on a network, allow for easier upgrading of the program on a single file server, instead of upgrading individual workstations.
3. Security: Sensitive files and programs on a network are password protected (established for specific directories to restrict access to authorized users) or designated as “copy inhibit” so that you do not have to worry about illegal copying of programs.
4. Centralized Software Management: Software can be loaded on one computer (the file server), eliminating the need to spend time and energy installing updates and tracking files on independent computers throughout the building.
5. Resource Sharing: Resources such as printers, fax machines, and modems can be shared.
6. Electronic Mail: E-mail aids in personal and professional communication. Electronic mail on a LAN can enable staff to communicate within the building without having to leave their desk.
7. Flexible Access: Access their files from computers throughout the firm.
8. Workgroup Computing: Workgroup software (such as Microsoft BackOffice) allows many users to work on a document or project concurrently.

Disadvantages of a Computer Network

1. Server faults stop the application from being available
2. A network fault can cause a loss of data
3. A network fault could lead to a loss of resources
4. User work is dependent upon the network
5. The system is open to hackers
6. Decisions tend to become centralized
7. Could become inefficient
8. Could degrade in performance
9. Resources could be located too far from users
10. Network management can become difficult