The S-VHS Format
S-VHS (Super VHS) was introduced in 1987 to fill a gap in the market between casual home users and video professionals. S-VHS uses both higher resolution (400 lines) and higher bandwidth than VHS, resulting in a significantly better picture quality. S-VHS also uses s-video connections, separating chrominance and luminance signals.
The transition to S-VHS required new equipment — both tapes and recorder/players. S-VHS equipment is backwards-compatible, meaning that S-VHS machines can play VHS recordings but VHS machines cannot play S-VHS.