A computer network or data network is a telecommunications network which allows computers to exchange data. In computer networks, networked computing devices exchange data with each other using a data link. The connections between nodes are established using either cable media or wireless media. The best-known computer network is the Internet.

Network computer devices that originate, route and terminate the data are called network nodes. Nodes can include hosts such as personal computers, phones, servers as well as networking hardware. Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other.

Computer networks differ in the transmission medium used to carry their signals, the communications protocols to organize network traffic, the network’s size, topology and organizational intent.

Computer networks ensure storing files in one computer and accessing those from other computers connected to the network. Moreover, it support an enormous number of applications such as access to the World Wide Web, video, digital audio, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications as well as many others. In most cases, application-specific communications protocols are layered (i.e. carried as payload) over other more general communications protocols.

A network is a group of two or more computer systems linked together. There are many types of computer networks, including the following:

@ local-area networks (LANs): The computers are geographically close together (that is, in the same building).

@ wide-area networks (WANs): The computers are farther apart and are connected by telephone lines or radio waves.

@ campus-area networks (CANs): The computers are within a limited geographic area, such as a campus or military base.

@ metropolitan-area networks MANs): A data network designed for a town or city.

@ home-area networks (HANs): A network contained within a user’s home that connects a person’s digital devices.

Computer Network Diagram:

Network Characteristics:

In addition to these types, the following characteristics are also used to categorize different types of networks:

# topology : The geometric arrangement of a computer system. Common topologies include a bus, star, and ring. See the Network topology diagrams in the Quick Reference section of viontechbolg.

# protocol : The protocol defines a common set of rules and signals that computers on the network use to communicate. One of the most popular protocols for LANs is called Ethernet. Another popular LAN protocol for PCs is the IBM token-ring network .

# architecture : Networks can be broadly classified as using either a peer-to-peer or client/server architecture.

Computers on a network are sometimes called nodes. Computers and devices that allocate resources for a network are called servers.