Computer networking is a process of sharing data and shared resources between two or more connected computers. The shared resources can include printer, Fax modem, Hard disk, CD – DVD Rom, Database and the data files. A computer network can be divided into a small or local area network, a networking between computers in a building of a office (LAN), medium sized network (MAN), a network between two offices in a city and Wide network (WAN) a network between the computers, one is locally and the other can be thousands of miles away in any other country of the world.

WAN connectivity is achieved by a network device known as “Router”. The internet is the world's largest WAN network, where millions of computers from all over the globe and connected with each other.

Networking is the practice of linking two or more computers or devices with each other. The connectivity can be wired or wireless. A computer network can be categorized in different ways, depends on the geographical area as mentioned above.

There are two main types of the computer network client-server and peer to peer. In the client server computing, a computer plays a major role known as server, where the files, data in the form of web pages, docs or spread sheet files, video, database & resources are placed.

All the other computers in the client/server network are called clients and they get the data from the server. In the peer to peer network all the computers play the same role and no computer act as a centralized server. In the major businesses around the world client-server network model is in major use.

A network topology defines the structure, design or layout of a network. There are different topologies like bus, ring, star, mesh, hybrid etc. The star topology is most commonly used network topology. In the star topology, all the computers in the network are connected with a centralized device such as hub or switch. Thus forms a star like structure. If the hubs/switch fails to work for any reason then all the connectivity and communication between the computers of a network will be halted.

In the network, a common communication language is used by the computers and the network devices and this language is known as protocols. The most commonly used and popular protocols on the internet and in the home and other networks is called TCP/IP. TCP/IP is not a singleprotocol but it is a suite of several protocols.

A network can be a wired or wireless and TCP/IP protocol can work both in types of network.

A data flow in a computer network can be divided into seven logical layers called OSI layersmodel that was developed by Intel and Xerox Corporation and was standardized by ISO.

1. Application layer

2. Presentation layer

3. Session layer

4. Transport layer

5. Network layer

6. Data Link layer

a. Media access control sub-layer

b. Logical link control sub-layer

7. Physical layer.

A network can be divided into different scales and ranges and it depends on the requirement of the network and the geographical location. Computer Network can be divided into Local Area Network, Personal Area Network, Campus Area Network, Wireless Local Area Network,Metropolitan Area Network and Wide Area Network.

There are several network connection methods like HomePNA, Power line communication, Ethernet and Wifi connection method.A network can also be categorized into several different types based on the services it provides like Server farms, Storage area networks, Value control networks, Value-Added networks,SOHO network, Wireless network and Jungle networks.


Source by Bushra Bashir