1. NETWORK The inter- connection of one station to many station is called Network. COMPUTER NETWORK  The inter-connection of the two or more connection, connected by communication line(Medium) to share resources like- H/W., S/W. and Other peripheral devices that is known as C.N.. TYPES OF COMPUTER NETWORK  There are three types of computer network are as follow:- 1. Local Area Network (LAN) 2. Metropolitan Area Network (MAN) 3. Wide Area Network (WAN)

2. 1.LAN:- They are very small networks with in the single building or campus. The data rate is –Mbps(100Mbps) or It provide high speed It cover an of less then 5KM Twisted pair cable, coaxial cable and fiber optical cables are used in LAN

3. 2.MAN:- It is used to connect different LANs in a city; Suppose we have different branches of company. We need to connect all those branches and all these branches have their own network. MAN provide data rate is 32Mbps to 150Mbps which is not very slow as compare to LAN.

4. 3.WAN:- WAN is the connection of two or more computers which geographical dispersed. WAN uses public network like- Telephone network for communication facility. Most WAN are used for transferring large blocks of data between the users.

5. NETWORK TOPOLOGY  It is the way in which the computers are connected in a network is known as topology.  Network topology is the arrangement of the various elements(Links,Nodes,etc) of a computer network. There are five types of network topologies are as follows:- 1. Star Topology 2. Ring Topology 3. Tree Topology 4. Bus Topology 5. Mesh Topology

6. 1.Star Topology:- It consist of several devices or computers connected to one centralized computer (client server network).

7. 2.Ring Topology It has consist of several devices or computers, connected to each other in a close loop by a single communication channel. There is no need of server.

8. 3.Tree Topology In this topology has computers are connected in hierarchical form and requires information to flow through the branches. Each computer is controlled by its upper level computer.

9. 4. Bus Topology It is also known as Horizontal topology. In this network, Each computer is connected to a single communication line or cable. In this topology, If the transmission channel fail the entire network fail.

10. 5.Mesh topology In Mesh topology, every device has a dedicate point to point link to every other device. Also due to point to point links make fault diagnose(Solve) easy.