Found this infomation from magnavox.com website.
There are three types of video connections that offer different levels of video quality:
Component Video (Best Quality)
Component video provides the best color separation, using the full bandwidth of black and white to produce the sharpest image. Red, green and blue signals are divided between the Pb and Pr cables, and the black and white signal is passed through the Y cable. The jacks on your TV set may be color-coded as (Pb) blue, (Pr) red, and (Y) green. Alternately, the TV jacks may be labeled Cb, Cr and Y.
S-Video (Better Quality)
S-Video is short for Super-Video. It is an available connection on most DVD players. S-Video is a high-quality method of transmitting video signals over cable to a television. S-Video separates information into two signals: Chrominance (color) and Luminance (brightness). This prevents color bleeding and the moving line of dots between colors, a phenomenon described as ‘Dot Crawl’, and increases clarity and sharpness. Once the information is finally delivered to the TV, it is done so as a single signal over one wire.
Composite Video (Good Quality)
The yellow composite video connector is typically part of a three-cable bundle that includes the red and white audio connectors. Older TV sets may only have this video connection available.
A composite video input combines the black and white component (Y) and the color difference component (C) into one signal. With these components combined into a composite signal, they cannot be separated once the TV set receives the signal. Thus, color separation is not sharply defined, and the edges of color images may exhibit ‘Dot Crawl’.