Sexual assault is when two people come in contact of a sexual nature, but one of the two people does not want this contact to happen. In some cases, one of the people involved may also be unable to consent to the contact. For example, they might be too young to consent. Rape is one form of sexual assault, but not the only one.
Different countries have different definitions of this. It is illegal but is not usually punished. In some places the crime of sexual assault has replaced the crime of rape.
A 2010-2011 study in the United States of 1058 people aged 14 to 21 found that 8% had sexually assaulted in their lives. In all cases the victim and the perpetrator knew each other. In 66% of cases no one found out and the perpetrator didn't get into any trouble. 50% said that their victim was completely to blame. 2% had raped and 3% had tried to rape.