Introduction to Computer Communication and Networks

Computer Network:-   computer network is a system of interconnected computers and peripheral devices.
eg: it may connect computers, scanners, printers and cameras.

-> A large number of computers are interconnected by copper wire, fiber optic cable, microwave and satellite.
-> A system consisting of connected nodes made to share data hardware and software is called, computer network.


-> Communication is about the transfer of information from a sender ,across a distance, to a receiver.



Applications of Network:-

following are the areas where computer networks are employed-

1. Electronic data interchange
2. Tele-confrensing
3. Cellular telephone
4. Cable television
5. Reservation of trains.buses,airlines etc.
6. Telemedicine
7. ATM
8. Internet banking



Advantages of Networking:-

1. Can shared data.
2. Can shared resources.
3. Can sharing devices and software
4. Can exchange information
5. Can communicate with each other



Components of communications:-

1. Hardware - computers, hub, switch, router, NIC, wired, wireless.

2. Software - operating system, applications: google, yahoo, msn




Network communication channels:-

Twisted pair wire
Coaxial cable
Fibre -optic cable
Satellite systems
Wireless systems (radio wave, microwave, infrared)



Modes of Communication:-

1. Point to point:-
                             -> Dedicating (simplex, half-duplex, full-duplex).
                             -> shared (multiplexing).


2. Broadcasting:-
                             -> Dedicating (channel level- one way)
                             -> shared (multiple access)
                                                shared between multiple access and some protocols are used that how they are using.



3. Multicasting:-

                           -> it is between the point to point and broadcasting
                           ->Communication to the specified group but not to others.