By the term communication, we mean the process of transferring massages from one point to another .

There are three basic element of any communication system.


1.Sender (sources)

2.Medium (carries the massage)


There are three nodes (ways) of transmitting data from one point to another. The data  can be transmitted by a communication medium in three nodes.



It this node of transmission, A simplex communication system can transmit data in one direction only. Devices connected to such a circuit are either send-only or receive-only in which flow of information. keyboard attached to a computer can send data to the computer.

Half duplex


A half-duplex communication system can transmit data in both direction, but in only one direction at a time. Hence, it can alternately send and receive data. It require two wires. It is most also for connecting communication using telephone in which one person speaks at a time. It can only one person response at a time.

Full duplex


A full-duplex system allows transmission it both direction simultaneously. This mode is also called as “two way simultaneously”. It requires four wires.