Can someone please explain Genesis to me?

(Longtime poser user – not a DS user) I never got into Genesis, I believed the stretching one a mesh too much isn’t a good idea.  And Genesis seemed to be all about stretching one mesh too far.  But now I’ve gotten a free copy of Victoria 6, and before I get started I need to understand this.

I thought everything Genesis was compatible with everything else Genesis.  I thought that was a whole idea.  But now I’m seeing products that are “for Genesis 2 female” or “for Victoria 6,” aren’t those the same thing?

I thought clothing, morphs, and textures for Genesis were supposed to be compatible with all other Genesis figures, what's Genesis 2 male vs. Genesis 2 female?  (I thought the only difference between those two would be a couple of morph targets!)

Are there texture differences between these models? Are morphs incompatible?

And if so, then what is the difference between Genesis and Unimesh/Millennium?

Like I said could someone please explain this to me? 

 

THX

z