How does Andover differ from Salem?

It's not clear exactly how the towns differ; however, Andover's citizens did band together to throw out the court.  They apparently had enough of the accusations and hangings.  It appears as Act IV progresses, that Salem's citizens will do the same. In fact, that is one reason Danforth wants Proctor to confess.  If he simply sets him free, it will prove that the court's findings were unjust.  This would give the townspeople, who are already growing tired of the proceedings, the initiative to overthrow the court.