One might easily conclude that the words arbitrator and mediator are completely the same simply because a mediator and an arbitrator share certain similarities in their work, but their roles when deciding over a conflict are totally different. A mediator is someone who negotiates between two parties seeking mutual agreement so as to end a conflict.
On the other hand, an arbitrator also shares a very similar function with a mediator just that both use different methods when settling disputes between two parties. A mediator is more committed to finding ways through which the conflict between two parties can be resolved. A mediator usually acts by initiating a discussion for the two parties to settle their differences and reach a mutual agreement.
A mediator can also make suggestions about things that look like solutions towards ending a conflict. In contrast, an arbitrator is someone appointed to judge or settle a dispute, and usually not by initiating or helping a discussion. An arbitrator will just listen to both parties and decide on the matter.