Computer monitors, on the other hand, are designed for RGB signals. Most digital video devices, such as digital cameras and game machines, produce video in RGB format. The images look best, therefore, when output on a computer monitor. When output on a television, however, they look better in S-Video format than in composite format.

To use S-Video, the device sending the signals must support S-Video output and the device receiving the signals must have an S-Video input jack. Then you need a special S-Video cable to connect the two devices.

S-Video FAQ
Answers to frequently-asked questions about S-Video, particularly with respect to PSX game machines.

Y/C and composite video signals - tutorial
This a non-technical tutorial on the format of Y/C (S-Video) and composite video signals. It is specific to the NTSC video system.