Will someone please explain to a pathetic noobie like me what the deal is with different lenses? For example, if I buy a Canon Rebel XT and the description says "Body Only" or "No Lens" am I correct in assuming that I would still be able to use it for all of my intents and purposes (basically, it would do the same thing my HP Photosmart does now), but I just wouldnt be able to do some of the fancy effects or stuff that you guys do? Please help! I've been reading up, hoping to start saving up soon for a new camera, but am rather lacking on the "basics" (also, what does SLR stand for?) Thanks!