NEWBIE need help understanding Seperates V Receive

Hi all!

Ok this is my first post, ive had home theaters set up before but im talking Bose etc. I have been doing some reading and I am now getting more into this as a hobby rather than a sit on the sofa and listen/watch type of thing.

So my first thing is I dont understand the terminology, like when I look on this site I see "pre-amps" "poweramps" "integrated" etc, what are these things and their role?

Previously I just used a receiver but the more I read the more I am into buying seperates, so what would I need to basically have a 5.1 or 7.1 set up without having a receiver but achieving the same goal as a receiver????

From what I know and please correct me, I need an amp and also the A/V processor.....is that it??? And obviously my speakers and sub.

But ive never had separates before so I am somewhat confused on that piece.

So for speakers I am hoping to go with B&W, the CM series or the XT series, the room is smallish 13x13x9H feet.

I will use the system for 50:50 Music:Movies

What combos would you recommend to power these B&W's and what brands?

Thank you for any input and sorry to be asking these questions!