Mage

''"Mages, incredibly powerful and yet exceptionally vulnerable, are able to deal out terrifying, awe-inspiring levels of damage, while taking little in return. They have command over the elements, summoning raging fireballs and chains of the coldest ice to wreak havoc over ranks of the enemy. They can even speak to our shattered planet, calling forth roots to bind enemies in place. However, Mages are also extremely weak, and so must learn to evade whenever possible." -AION wikia''

Sorcerers
A Sorcerer is the natural successor of the Mages. They have high levels of Magical Damage and can call upon raging infernos, storms, and blizzards to defeat their foes. They are also one of the best crowd controllers. They are weak in defense, though, and if caught can be destroyed fairly easy.

Sorcerers use Orbs and Tomes. Orbs provide more Magic Boost, which makes their spells even stronger, while Tomes provide Magical Accuracy to ensure that an enemy cannot resist their attacks.

Spiritmasters
Spiritmasters are agreeably the most unique Mage branch class. While they are cast spells, maybe not as devastating as their Sorcerer counterparts, they are able to summons Spirits that follow a Spiritmaster's every command. They are also the debuff specialist.

Spiritmasters can use Orbs and Tomes just like the Sorcerer.

On the topic of Spirits, there are four elemental spirits to call upon: Fire Spirit, which focuses on damage; Earth Spirit, which focuses on high defense and keeping the enemy on them while their masters send attacks; Wind Spirit, which is the fastest and best at stunning and enemy; and Water, which is the weakest in defense but highest in ranged magical attacks. There is also a fifth Spirit that depending on your race one can summon. The Elyos are able to summon a Tempest Spirit (Wind/Water) while Asmodian's can call forth a Magma Spirit (Fire/Earth). These two Spirits are extremely unique and can only be summoned for a maximum of 20 minutes with the required about of DP.