The game has nine character classes that a player can choose from, though not all classes are available for each race. Each class has a set of unique abilities and talents. Abilities are general skills and spells available to the entire class, while talents allow players to specialize their character and further refine their role. Each class has a set of three talent trees. Depending on class, players may choose to build their character’s talent trees for damage-dealing (also called damage-per-second, DPS), healing, tanking, or a mix of these. Some classes, known as “hybrid classes,” are able to perform different roles depending on a group’s needs.^[12]

The nine available classes in World of Warcraft are:

• Druid: Hybrid class. A nature-oriented class capable of fulfilling the role of damage-dealer, tank, or healer. The druid can shape-shift into many forms to increase its combat or movement abilities, such as a bear (for tanking), a “moonkin” (for ranged magical damage), and a seal (for water travel).
• Hunter: Damage class. A combination of a marksman/archer and animal specialist, the hunter specializes in ranged damage dealt by means of a bow, crossbow, or gun with the help of an animal pet. The hunter also employs a series of traps for damaging or disabling enemies.
• Mage: Damage class. The wizard-esque damage-dealer of World of Warcraft, the mage employs spells of the “arcane”, fire, and frost elements. Mages can also conjure food and water to replenish group members, and teleport themselves and others to most major cities.
• Paladin: Hybrid class. A heavily-armored holy warrior. Like druids, paladins can specialize to fulfill each of the three major roles in World of Warcraft. (See also: Paladin (character class).)
• Priest: Healer/damage class. A lightly-armored class that can protect and heal allies (with “Holy” spells) or bring harm to enemies (with “Shadow” spells).
• Rogue: Damage class. A shadowy assassin that can “stealth” to avoid being seen by enemies (providing near-invisibility). The rogue deals damage by dual-wielding small melee weapons, and also provides traditional thief skills like lockpicking, picking pockets, and poison use.
• Shaman: Hybrid class. Unlike other hybrid classes (paladins and druids), the totem-wielding shaman’s tanking abilities are quite limited. However, they can specialize to become effective healers, or damage dealers using either melee weapons or spells.
• Warlock: Damage class. Essentially a sinister combination of the mage and the hunter, the warlock deals magical damage like a mage but also has demonic “pets” (called minions) like hunters. Depending on their specialization, the warlock’s damaging spells can come chiefly in the form of “damage over time” spells that, after being placed on an enemy, slowly deal their damage, or in the form of direct damage spells that deal damage all at once, as those of a mage or shaman do.
• Warrior: Tank/damage class. A heavily-armored class, the warrior is a general melee fighter who can use any non-magical weapon in the game and who can specialize to be either a damage dealer or a tank.

The Paladin class was previously only available to the Alliance, and the Shaman only available to the Horde. Now, with the release of The Burning Crusade, the Draenei (Alliance) are able to be shamans and the Blood Elves (Horde) are able to be paladins, removing the previous faction exclusivity. In the Wrath of the Lich King expansion, a tenth class known as the Death Knight will be added, which will also be the game’s first Hero class.

Content borrowed from wikipedia.org