An RCA connector, sometimes called a phono connector or cinch connector, is a type of electrical connector commonly used to carry audio and video signals. The name "RCA" derives from the Radio Corporation of America, which introduced the design by the early 1940s to allow mono phonograph players to be connected to amplifiers. They began to replace the older TRS connectors (also called jack plugs) for many other applications in the audio world when component high fidelity systems started becoming popular in the 1950s. The connection's plug is called an RCA plug or phono plug, for "phonograph". The name "phono plug" is sometimes confused with a "phone plug" which refers to a TRS connector plug.