Telecommunication circuit

A telecommunication circuit is any line, conductor, or other conduit by which information is transmitted.

A dedicated circuit, private circuit, or leased line is a line that is dedicated to only one use. Originally, this was analog, and was often used by radio stations as a studio/transmitter link (STL) or remote pickup unit (RPU) for their audio, sometimes as a backup to other means. Later lines were digital, and used for private corporate data networks.