Composite is that yellow video cable and gives the worst picture quality. S-video gives better standard definition (480) picture quality. Component (blue,red & green) and HDMI transmit SD and HD (480,720,1080). The ability to upconvert DVDs is something that’s restricted by the DISC to the HDMI input. A few discs don’t have the restrictive software and can be upconverted over component.
HD DVD players and discs work just fine over component.
I don't know why I keep getting those two mixed up, I had meant to say the Component cables.........thanks