Basic of Computer Networks

Computer network is a telecommunication channel through which we can share our data.
distributed system
A network must be able to meet certain criteria, these are mentioned below:
Performance
Reliability
Scalability
Components of Data Communication
Message : It is the information to be delivered.
Sender : Sender is the person who is sending the message.
Receiver : Receiver is the person to him the message is to be delivered.
Medium : It is the medium through which message is to be sent for example modem.
Protocol : These are some set of rules which govern data communication.

Two ways to connect the devices :
Point-to-Point connection
Multipoint connection

Point-To-Point Connection :  It is a protocol which is used as a communication link between two devices. It is simple to establish. The most common example for Point-to-Point connection (PPP) is a computer connected by telephone line. We can connect the two devices by means of a pair of wires or using a microwave or satellite link.
MultiPoint Connection   : It is also called Multidrop configuration. In this connection two or more devices share a single link.
There are two kinds of Multipoint Connections :
If the links are used simultaneously between many devices, then it is spatially shared line configuration.
If user takes turns while using the link, then it is time shared (temporal) line configuration.