That answers that :)
Thanks OP for asking this, I was curious as well.
So calibre is a tool used to produce a nice organized library from whatever you dump into it. Kinda like iTunes, as opposed to foobar.
It's good to know I can just copy everything into calibre and then delete the original folder once I'm satisfied with the calibre library and have it backed up somewhere. (I use portable so this is a simple matter of copy/paste.)