What is a svideo cable for?

A s-video cable provides a connection for Super Video, which is a higher quality video signal than the more common composite video (usually the yellow phono jack marked Video). The Super Video signal provides two components of the composite video signal separately for better resolution and color rendition. The two components, luminance (Y) and chrominance (C), are carried on two parallel coaxial wires in the s-video cable. The four pins in the connector are for Y, Y ground, C, C ground.