A transceiver is a device that can both transmit and receive signals, commonly used in communication systems. It combines the functions of a transmitter and a receiver, allowing for two-way communication. Transceivers are found in various applications, including telecommunications, radio, and networking equipment. In networking, transceivers are essential for connecting devices like computers and routers over different types of media, such as fiber optics or copper cables. They convert electrical signals into optical signals and vice versa, enabling data to travel efficiently over long distances.