Composite Video Description

A single "Yellow" (shielded) RCA jack [75 ohm coax cable], which is not to be confused with the Audio (Red and White) jacks
of the newer three cable systems, or just a single black wire in the older systems.
The term Composite is used because it's a composite of the black-and-white information (Y) and the color information (C).
Composite Video may also be called VBS [Video, Blanking and Syncs], or CVBS [Color, Video, Blanking, and Sync].
The video signal is on the yellow cable, while the white carries the left audio and the red carries the right audio.
Composite video is only used on the Yellow cable, but it's common for the audio cables to be bundled in a three cable assembly.
S-Video is better than Composite Video, and Component Video is better than either of them.
S-video is a round DIN connector, Component video is a 3-cable [video-only] interface, and Composite Video is a single yellow cable.

Composite Video Interconnection

Although the Composite Video interface is still found on Audio-Visual gear as of 2010, you don't want to use it.
The next better video interface is S-Video [below], again the A/V gears needs to have the interface.
Of course if you have no other option, than Composite video will suffice. However these days Composite Video is used a little differently.
The Composite Video interface is used in combination Component Video, as the audio input.
Recall that Component Video, is video only, with no audio input. So an audio cable is still required with 3-wire Component Video.
Although the Red and White audio cables are not "composite" video cables, their only attached to the yellow cable as an assembly.
So when you use Component Video between devices, you may also be using the white and red cables of Composite video to hold the left and right audio channels.

Composite Video on a Blu-ray Player Rear Panel

Because in some cases either the Audio or Video is used by them selves, the yellow video connector may be off-set a bit or not even present. The Red and White Audio connections could be used with the Yellow Composite video line, the Green, Blue, Red Component Video connectors, or the Orange Coaxial video connector.

These days, the HDMI cable is the one you want. But you still need to retain compatibility with your old gear. The 2010 Blu-ray player shown above comes with four different video options; Composite, Component, HDMI, and Coaxial. While the older AV Receiver below has 7 composite channels, 5 S-Video channels and 3 Component video channels.

Composite Video Alternatives

This particular A/V receiver contains four different video and audio Composite Video channels.
An A/V input for a TV or Satellite connection and an A/V input from a DVD player.
Also two sets of auxiliary A/V channels that are used as both input and output Composite Video channels.
Each channel follows the Composite Video color format having video as yellow, and audio by white and red.
Note that this receivers provides the option of using an S-Video DIN connector instead of using the Composite Video RCA jacks.
Also note that the receiver provides three sets of RCA jacks used by component video, to the upper right of the unit [Green, Blue and Red].
The multi-pin yellow connectors, used for S-Video, at the top of the unit should not be confused with the single-jack RCA connectors just below.