A Transceiver is a device which can be both used for transmission and receiving purposes. Some devices are also called transmitter-receiver, but they are different from transceiver as they don't share common circuitry or single housing whereas transmitter and receiver within a transceiver share common circuitry or a single housing. There are many types of transceivers: RF transceivers, fibre-optic transceivers, Ethernet transceivers, wireless (WAP) transceivers, and more but here we are mainly concerned with RF transceiver for satellite purposes. <br \>

[[File:Avengers.png|thumb|Above is a scene from Avengers 2, in which Black Widow is transmitting Morse code to communicate, and Hawkeye is using the transceiver to receive the signal. ]]

A modem is similar to a transceiver, in that it sends and receives a signal, but a modem uses modulation and demodulation. It modulates a signal being transmitted and demodulates a signal which is received. <br \>

In a radio transceiver, the receiver is silenced while transmitting. An electronic switch allows the transmitter and receiver to be connected to the same antenna and prevents the transmitter output from damaging the receiver. With a transceiver of this kind, it is impossible to receive signals while transmitting. This mode is called half duplex. Transmission and reception often, but not always, are done on the same frequency. <br \>