LCD? Plasma? Rear projection? LCD Rear projection? GAH! What is the difference?

Ok, I am getting to be in the market for a bigtime TV upgrade for my home theater. I will probably try to get one with a DVI input and everything too, but I am confused on something. I see out there the standard rear projection big screens. Then I see LCD rear projection big screens. Then I see plasma tv's. And after that I see LCD TV's. I need to know what the difference is. Ok, on the plasma and regular LCD I pretty much know what is down with those, but what the heck is a LCD rear projection TV and how does it differ from a normal rear projection? And how does it differ from a normal LCD besides being as big as your normal rear projection type? Thanks for any help if you are in the know!