The Usages of Models?

[Rosencrantz]

topic title

So I'm just wondering about something:

What was the function of "The Spriter's Resource" to begin with?
Simple. To provide a database for all the sprites of various sprite-based games for people to use. Sprites are incredibly easy to use, seeing as how
well
you could plop them into virtually any graphics program and manipulate them as you see fit.

This then led to sprites having a multitude of usages, ie. from being used in sprite comics, in fan games, in graphics for avatars/sigs/what have you, and things of that nature.

But then the question comes in:
how are we supposed to even *use* models?

Are they pre-made so that you could open a 3D program like Maya or Blender and then make an animation using them? Or will we have to do that ourselves? (which, in that case, it would be good to have tutorials for things of that nature)
Are they rigged so that you could easily import them into a Source game (either as model replacements for games like Counter-Strike or ragdolls in Gmod)? If not, will there ever be tutorials for us to use them like that?
And what else could models be useful for?

I'm just asking this from the point of view that I have no understanding of models whatsoever