Dazed and confused about YPbPr- S-video, chrominance, luminance

[mrwebber35]

I understand chrominance is the colour part of a S-video cable. I've read that it is a combination of (red)Pr and (blue)Pb on component cables. I've also read that just Pr or just Pb is chrominance. Does that mean if you jumper the two together directly it creates the chrominance on a S-Video cable? Is the green or the Y of YPbPr directly the same as the luminance on a S-Video cable? If the above is all or partly true then is it OK to have the grounds on the S-Video cable the same ground on pins 1-2?

My situation is I have a new cable box that doesn't have a pinout for a mini din that does have YPbPr output with RH and LH audio and is marked as "analog". I bought the cable and it does as it should and functions dividing red blue and green. Can someone explain if Y(green) is the same as pin 3 and PbPr the same as pin 4 on a S-Video cable?

https://en.wikipedia.org/wiki/S-Video