A computer network is nothing more than two or more computers connected together in order to share information. It's a simple but very powerful concept. Networked computers (also called nodes, clients, workstations, and servers) perform three key functions; they share files, resources (printers, disks, etc.), and programs. Each node has its own unique hardware address to identify it on the network.

A networked computer that provides resources is called a server. The computer accessing those resources is called a workstation, a node or client. Servers are usually the most powerful computers on the network because other computers share their resources.

Workstations are usually PCs, which are cheaper and less powerful. A computer may be a server or a workstation but rarely both. Keeping this separation; greatly simplifies management and administration of the network. Other network components include the network interface card (NIC), which transmits and receives information, and the cabling, which physically connects the computer to the network. Network implementation mostly falls into two categories:

Another type of network that there is named MAN (Metropolitan Area Network)