Violence and Assault can be used interchangeably.  

There are different types of sexual assault. It can include but is not limited to…

The assault can be historic where it may have happened in their childhood, adolescence and perhaps even as adults. There is a victim-blaming environment at times and this must be addressed. 

One of the biggest when it comes to childhood sexual abuse is: Should it happen to my child, s/he would tell me right away. This is false. 

Most important thing you can do is believe the person is telling you and thank them for opening up to you.