Rubber bands between teeth for braces?

So, my dentist said that she'll put rubber bands between my back teeth for 6 months if this method doesn't work then she'll remove 2 of my teeth...(SHT!!!!!!)what do rubber bands help you? I also heard about rubber bands make gaps between your front teeth(?) is that TRUE? o.o what if the rubber bands break while I'm at home? will it affect my teeth?? :'(