I've been hearing about Carrara some off & on the last few months, but as a beginner I'm confused about the exact purpose of Carrara compared to DAZ.  I understand that DAZ created the people, animals & various other creatures(monsters, dragons, architecture, vehicles, etc), but what exactly does Carrara do that DAZ does not? What's the difference exactly?

Someone recommended C8 to me because apparently it handles "Collision Detection" better than DAZ, and the GUI is supposedly different, but other than that, is there a reason I should use Carrara along with or instead of DS4?

In the descriptions of the programs at DAZ, the precise advantages or differences of the various programs are really not spelled out. Also, a related question, what does Hexagon do that neither of the above do? Or Lux Render vs Reality. Is Hexagon more closely related to Bryce or something else?

Also, does Carrara have any real manuals or documentation? Because we all know DAZ has practically none except for a few tutorial videos.