Arenas are places where you can fight in groups. Game modes are: 2 vs. 2, 3 vs. 3 and 5 vs. 5. To begin the fight, you have enroll your team. You can’t enter solo and wait for a partner. When you register, enter the queue.
Remember that you can be in one time in each mode. System chooses enemies at the same level. It examines your level basing on amount of points of your team.
In fight, you have a finite number of respawns. You have to force enemies to use all of them first. Fights take place on small arena, because producers think first of all about dynamic battles.
You decide about the members of your team, so you can have three healers or three tanks if you want to. On arena you fight against other players, there is no additional goal.