Introduction to Computer Network

Introduction
A computer network is an interconnected collection of devices that enables one to store, retrieve, and share information. Commonly connected devices include personal computers, minicomputers, mainframe computers, printers, fax machines, pagers and various data-storage devices. Recently, other types of devices have become network connectable, including interactive televisions, videophones, handheld devices and navigational and environmental control system.

To be more precise a network is a group of computers that are connected in some fashion to allow the computers to communicate, share files, printers and other resources. A network consists of the following components:

• Server(s)
• Workstations or clients
• Network Interface Cards or NIC's
• Communication Medium

A group of two or more computer systems linked together is networking.

Servers are specialized computers that act as a host to client Machines and provide services like printer and file sharing. Peer to peer networks don't have dedicated file servers.

A file server is a combinations of computer, internal hardware, and software that allows network users to share computer programs and data. It may also have a tape back-up unit, modems and several printers attached.

A file server is a computer which is based for storing files. Any user on the network can store or retrieve files on the server with some request.

Workstations or Clients are the computers that are on the network. Sometimes client is called a 'node'. Workstation is a Personal Computer which is connected to the network and which rely upon the server for booting, file transferring and various other activities.

In Network Interface Cards, a printed circuit board that plugs into both clients (personal computers or workstations) and servers, controls the exchange of data between them. The network adapter provides services at the data link level of the network, which is also known as the "access method". The most common network adapters are Ethernet and Token Ring. Sometimes, the Ethernet adapter is built into the motherboard. LocalTalk (A common protocol), which provides the data link services of Apple's AppleTalk Snetwork is built into all Macintoshes. A transmission medium, such as twisted pair, coaxial cable or fiber optic, interconnects all the adapters in the network. A network adapter is also called a "network interface card" (NIC).

Most NIC's are designed for a particular type of network, protocol and media, although some can serve multiple networks.

A Cable is a flexible metal or glass wire or group of wires. All cables used in electrical instruments are insulated with a material such as plastic or rubber. Cables are the main backbone in LAN. There are many kinds of cables available in the market. For example, Coaxial , UTP, STP, Fiber Optic etc,.