Duplex is a telecommunications term for communication channels that can be between two devices simplex, half-duplex, or full-duplex.
Half-Duplex: In this mode of transmission, both the sender and receiver can transmit and receive the waves but only one station can do at a time, or you can say that they both cannot do this at the same time. It’s also means that when the sender is sending the signals, then the receiver can only receive the signals. The same scenario happens for the other side also. We use this communication or transmission mode when we want a one-way communication.