template suggestions point to which template files?

Hi, I've recently downloaded Sections for my Drupal 6.16 install and I've been reviewing sections.module. In the code it is unclear to me whether Section's primary goal is to assign a new Theme entirely to a path (or set of paths using *) or if its goal is to influence template suggestions. Or is it some combination of both? It occurs to me that these are two very separate actions but it's obvious that sections_preprocess() implements a series of template suggestions for the theming engine.

Why are the suggestions there and do my themes have to implement the Section's template suggestions in order for Sections to work?

Thanks,

JR