S video ... ?

Y C or S video or SVHS  is one step up from composite video. It is found more often these days and definitely does produce a higher quality of picture than composite. The black and white or Luminance (Y) portion of the signal is sent separately form the colour or chroma (C) portion. This does avoid the nasty moiré patterning and give improved detail when compared with composite video. S video typically uses a four pin mini din connector but can be frequently found on scart connectors. Because the same pin (15) on the scart plug is for the colour as both input and output the socket cannot be bi-directional and must be configured as either an input or output.

Adaptors are available to convert from S video to composite and visa versa but these do not restore the lost picture detail. (make sure you get a filtered one like the Keene STOC)