1. Simplex Mode:- In this mode of communication, only one way communication is possible. Example is radio and television broadcasting. In this mode there is just one communication channel. so, we can receive data on that channel but could not be able to transmit on same channel.
Half-Duplex: In this mode of communication, two-way communication is possible but one at a time. If there is a location A and B so we can send data from A to B or from B to A but one at a time. Example is walkie-talkie or Push-to-Talk. In this mode there is also a single communication channel but it can be used in both direction for transmission.
3.Full-Duplex: In this mode of communication, two-way communication is possible in both directions simultaneously . It means data can be sent from A to B and from B to A at same time. Example is Telephone/Mobile Communication. We can listen and talk at same time on telephone. In this mode there are two communication channels one for each direction of transmission.