In radio communication, a transceiver is a device that is able to both transmit and receive information through a transmission medium. It is a combination of a transmitter and a receiver, hence the name transceiver. Transmission is usually accomplished via radio waves, but communications satellites, wired connections, and optical fiber systems can also be used.
Radio frequency (RF) transceivers are widely used in wireless devices. For example, cell phones use them to connect to cellular networks. Other common examples include walkie-talkies and CB radios. By combining a receiver and transmitter in one consolidated device, a transceiver allows for greater flexibility than what either of these could provide individually.
Despite the widespread use of transceivers, one common system that does not use them is FM radio. In FM radio, receiving and transmitting data are intentionally two separate jobs. Radio stations transmit music, news, and other data over analog radio wave signals (and, more recently, digital signals) and FM radios in homes and cars receive these signals for listeners to enjoy. This system restricts who is allowed to broadcast.