colour-difference signal BrE
color-difference signal AmE

As S-Video maintains the two as separate signals, but still encodes two colour-difference signals into one chroma subcarrier, such detrimental low-pass filtering for luminance is unnecessary, although the chrominance signal still has limited bandwidth, and the colour crosstalk problem is subdued.

Compared with component video schemes where separate Red, Green and Blue (or luminance and two colour-difference signals) are given their own cables, S-Video offers poorer quality, because the colour information encoding (with a subcarrier frequency of perhaps 3.57 to 4.43 Megahertz, depending on standard) limits the maximum theoretical chrominance bandwidth possible.