[edit] Mage Lore
Masters of Arcane, Fire and Frost magic, the mages of the Kirin Tor were scattered across the continents following the destruction of Dalaran by the Burning Legion. Mages in the World of Warcraft descend from influential, powerful denizens of Azeroth, that used their tremendous power to influence politics. Jaina Proudmoore, one of the central figures in the Warcraft storyline, is the most powerful mage still alive, depending on how you consider Medivh, whose whereabouts are unknown.

[edit] Gameplay
Mages are a magic-using class who use a host of magic-based power to attack their enemies. Although they can deal large amounts of damage in a short period of time, like rogues, survival is a challenge due to their low amount of hit points and limitation to cloth armor. The mage class’s combat tactics, survivability, and damage output vary drastically depending on how their talents are invested.

The arcane tree gives “utility” talents, such as passive increases and bonuses to mana, silences added to spells, increased armor, as well as spell damage. At higher levels, the arcane tree offers powerful spells designed to maximize the mage’s damage potential. To balance this raw power, the spells have “cooldowns” during which the mage cannot use them. The fire tree focuses on maximum damage output at the cost of survivability. A fire mage usually attempts to destroy the enemy before the monster is in melee range, whereas frost tree allows the mage to slow/freeze enemies, summon ice shields and elemental minions for a more controlled style of play.

A signature of the Mage class is its use of area-of-effect spells, creating circles and cones of force on the gamefield which damage, disorient, and/or slow down all targets caught within the area of effect. They also have the “Polymorph” crowd-control ability which can transform an unfriendly humanoid or beast target into a harmless animal until the spell wears off or the target takes damage.

Mages also have a variety of spells to boost party effectiveness. Mages can cast the Arcane Intellect and Arcane Brilliance buffs, which increase the mana pool and spell critical-strike chance of their targets. They can also conjure food and water for their teammates, which can be eaten outside of battle to speed up mana and health regeneration. Mages can teleport themselves and their party members to any capital city at using a cheap reagent.