Audi Alteram Partem is a legal maxim which literally means "Hear the other side". This rule means opportunity of fair hearing to the other side must be afforded before going for a conclusion about the guilt of a person e.g.

The other party must be called upon to explain against the allegations labeled against him, the other side must have a reasonable opportunity to adduce his evidence and to cross examine the witness of other side, order should not be recorded in the absence of other party etc.