If you’ve ever connected a CD player or DVD player to your TV, you’ve probably used an RCA cable. A basic RCA cable has three color-coded plugs sticking out of one end that plug into three corresponding colored jacks on the back of a TV, projector, or other output device. It carries audio and video signals from the component device to the output device (i.e., a TV or speakers).

RCA cable is named after the Radio Corporation of America, which first used it in the 1940s to connect record players to amplifiers. It became popular in the home in the 1950s and is still used today. The two most common types are composite video and component.

The colors used in composite RCA cables are usually red and white or black for the right and left audio channels, and yellow for composite video. Composite video is analog, or non-digital, and carries all of the video data in one signal. Since analog video is initially three separate signals, compressing them into one signal degrades the quality somewhat.

Composite video signals are generally 480i NTSC/576i PAL standard definition video signals. It is not designed to be used for high-definition analog or digital video signals.