Both assault and self defense relate to injuring another person.
Assault deals with the act itself, and self defense deals with making an excuse for the act.
If you committed the act of assault, you may not be found guilty if you have a legal excuse for committing the act. This is where self-defense comes into play. Basically, that means if another person is about to assault you, you may defend yourself from that attack. Your defensive act, although an assault itself, may be excused in these situations. The information contained in this site is made available as a public service to the general public and is not intended to serve as legal advice.