Thanks Walter and Andrew for your comments.
Andrew, thanks for the link to Martin's video. That was a very informative video. I really enjoy Martin's info, as I do yours, but since I do not use Lightroom, I had never seen it. I guess I should branch out a bit in my education....LOL. The different renderings of the image produced when using the main panel saturation slider set to -100 compared to the HSL sliders at -100 in reality are simply options that I can be aware of and select from in order to achieve the look I am seeing in my mind for the particular image. The artist part of me is screaming "don't wonder why.....just use it!", but the techie nerd/little boy in me still wants to know "why?".