Arbitration differs from mediation, just as mediation differs from a trial. In arbitration proceedings there is a decision maker, much like a judge. There might be more than one arbitrator in some kinds of arbitration proceedings. However, there is not any appeal from an arbitrator's award, and they are usually quite final. Also, it is not necessary for an arbitrator to explain the final award.
Arbitrations are more like trials, than mediation.
Mediation is not therapy. Therapy is done by mental health professionals, in an effort to aid people in becoming more comfortable with their feelings, and acting more appropriately in their daily lives. Mediators conduct mediation. Their task is to make it possible for people to have successful negotiations, leading to a settlement of their dispute. Counselors, usually trained mental health professionals or clergy, listen and give advice.