This is from RAIIN and I will provide the link in case any one else wants to read further.
"Unfortunately, sexual assault can come in many forms. In order to better understand the wide range of personal violences that can occur, we have included definitions of different types of rape and sexual assault, as well as other kinds of violence that often arise hand-in-hand with sexual assault. Click on the title below to read more about each type of sexual assault."
http://www.rainn.org/get-information/types-of-sexual-assault