Computer Networks

A Computer network is a collection of interconnected computers. Two computer are said to be interconnected if they are able share information.

What is the need for networking:-
1) Sharing of files and software
2) Sharing storage
3) Improving communication

Type of Networks:-
1)PAN:- personal area network connects devices that is around a single individual such as a laptop, mobile phone, desktop etc.. Personal area networks can be constructed with cables or wirelessly.
USB and FireWire technologies often link together a wired PAN while wireless PANs typically use Bluetooth or sometimes infrared connections. Bluetooth PANs are also called piconets.
Personal area networks generally cover a range of less than 10 meters.

2)LAN:-Local area network provides networking capabilities to a small group of computers in close proximity to each other such as in an office building or in a school.
LAN is useful for sharing resources like printers, files, games and other applications. LAN can be connected to the WAN(wide area network) or Internet.
Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, network adapters, and hubs.

3)WAN:-wide area networks cover a large physical distance. The internet is the largest WAN spread around the earth. A WAN is basically a collection of LAN from all around the earth.
A network device called router connects LAN to router. WANs tend to use technology like ATM, Frame Relay and X.25 for connectivity over the longer distances.

Network Topologies:-
1) Bus topology:- this topology uses a common single cable to which all the computers (workstation) in the network are connected. Each computer performs its task of sending messages without the help of the central server.
However, only one workstation can transmit a message at a particular time in the bus topology.
2) Star topology:- In this topology all the computers in the network are connected to central hub or switch.
3) Tree topology:- this topology combines the characteristics of bus topology and the star topology. The networks looks like an inverted tree with the central root branching and sub branching down to the workstations.
4) Mesh topology:- In this topology every computer in the network can be connected to every other computer in the network.
5) Ring topology:- The type of network topology in which each of the nodes of the network is connected to two other nodes in the network and with the first and last nodes being connected to each other.

For more information on Computer Networks click the following links:-

some of the questions that came to my mind while I was doing the research are:-
Q.1)What is circuit switching and message switching?
Q.2)What is a NIC(netwrok interface card)?
Q.3)What is the scope of Computer networks in the furure?

sources:- wikipedia,Computer-Networking-Principles-Bonaventure