indepth component description

I'm new to GH and would like to find a "place" for detail information on the components.

For example, I want to generate G-code and I'm following a very good tutorial on making tool paths.  One of the componets in the description is "Srf CP".  I understand the input and outputs, but why do I need to convert my points to UV coordinates? 

I've read the primer from Payne and Issa.  Good reading, but I want to understand why I'm using these components.  Do I need to re-read the primer a third time?  :)

Anyways, thanks for the help.