MODEM

The modem is a contraction of the term modulator and demodulator.as the name suggests a modem performs functions of both modulator and demodulator.
modems are described depending upon their mode of operation.the modems can be used to transmit and retrieve the data in the following three modes:
(1.) SIMPLEX MODE- it is mode of using a modem in which data signals can be transmitted b/w the transmitter and the receiver in only one direction.
(2.) HALF DUPLEX- it is the mode of using a modem in which data signals can be transmitted b/w the transmitter and the receiver in both the direction at a time.
(3.)FULL DUPLEX- it is the mode of using a modem ,in which data signals can be transmitted b/w the transmitter and the receiver in both directions at the same time.