Computer networks

Computer networks

A computer network is a collection of computers terminal devices connected together by a communication system. The set of computers may include large-scale computers, medium-scale computers, minicomputers, and microprocessors.

The set of terminal devices may include intelligent terminals, "dumb" terminals, workstations of various kind and miscellaneous devices. 


1. Share resources from one computer to another.
2. Create files and store them in one computer, access those files from the other computers connected to the network.
3. Connect a printer, scanner or a fax machine to one computer within the network and let other computers of the network use the machines available over the network.

computer network

    Following is the list of hardware required to set up a computer network 

Network cables are used to connect computers.the most commonly used cables are category 5 cable RJ-45.


Each and every computer can be connected to another one via a serial port but if we need to connect many computers to produce a network, this serial connection will not work.The solution is to use a central body to which other computers, scanners etc.Can be connected and then this body will manage or distribute network traffic.


A router is a type of device which acts as the central point among computers and other devices that are part of a network.a router is equipped with holes called ports.Computers and other devices are connected to a router using network cables.Nowadays router comes in wireless modes using which computers can be connected without any physical cable.


The Network card is a necessary component of a computer without which a computer cannot be connected to a network.Also known as network adapter or network interface card.Most of the branded computers have network card pre-installed.Network cards are two types internal and external network cards.

The motherboard has a slot for internal network card where it is to be inserted.Internal network cards are of two types.The first type uses peripheral component interconnect(PCI) connection.The second type uses industry standard architecture(ISA).Network cables are required to provide network access. 

Comes in two flavors. Wireless and  USB based.Wireless network card needs to inserted into the motherboard but no network cable is required to connect to the network.USB card is easy to use and connect via USB port.The computer automatically detects USB card and can install the drivers required to support the USB network card automatically.


There are many types of networks.However, from an end- user's point of view, these are of three basic types.The three basic types of computer networks are as follows .......

1.Local Area Network(LAN)

In this types of network, the different nodes are at most 1KM apart. Generally, LAN is preferred for short distance communication. e.g., between two rooms of the same building or within the same company premises.
Example- Novell Network.

2.Wide Area Network(WAN)

Here, the different nodes are geographically far apart from one another, separating two cities or two states or even two continents. The method of communication in WAN is through logical channels. Actually, the origin of WAN was from ARPANET(advanced research project agency network).
Example- Internet.

3.Metropolitan Area Network(MAN)

A metropolitan area network is larger than a LAN. Its features are similar to both LAN and WAN. It is called metropolitan since it normally covers the area of a city.Different hardware and transmission media are often used in MANs because these must efficiently cover the distance(a few tens to about one hundred kilometers) or because these do not require complete access to locations between the network sites.
Example- Cellular Phone, Pager etc.

In addition to these types, the following characteristics are also used to categorize different types of the network.


Topology is the geometric arrangement of a computer system. common topologies include a bus, star, ring etc.


The protocol defines a common set of rules and signals used by computers on the network 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.


Networks can be broadly classified as using either 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.


In computer terminology, a bus is a circuit that carries data from one component to another.

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