Mediation, first and foremost, is a form of conflict resolution. Usually, it has advantages over the more familiar legal formats of trials and arbitrations, or even informal negotiations.
Mediation is all the things listed above.
Not at all. Anyone who has been through a courtroom battle can tell you that there is a cost for this method far beyond the price tag in dollars. The outcome does not feel like a solution, still less a resolution. The winner, however, usually feels beaten also, as soon as the initial sense of triumph wears off. Unless the loser is a very large, very wealthy corporation, there may never be payment of the monetary awards trials give.