To submit to something means to undergo or accept it. You must submit to a search if the police have a warrant.
Many of the senses of submit are variations on that first meaning of acceptance. When you submit an application, you formally hand it in to be judged. Similarly, if you put something before an organized group, you submit it. Often websites will have an e-mail address where you can submit questions, comments and suggestions. If you want to paint your room black and your parents submit, they give in to your wish.