Race

The Warcraft universe is inhabited by many races of sentient and sapient beings. These races speak many different languages, have different homelands and racial traits, and can pursue different classes.

Though most races are native to the world of Azeroth, some have arrived from other worlds, such as Draenor. The armies of the Burning Legion are culled from many worlds throughout the Twisting Nether.

Currently, there are two playable factions in World of Warcraft, the Alliance and the Horde, and each is comprised of five very different races who can play a variety of different classes.

In Warcraft lore, race often has the same definition as species.[1] Occasionally, within a race/species are groups called subspecies/subraces[2][3][4] Note that use of race may not always denote seperate species however (and may refer to ethnicities/subraces/subspecies within species)
Base stats do not include the bonus scores from classes. The class bonuses are:

Attribute  Priest  Rogue  Warrior  Mage  Druid  Hunter  Warlock  Shaman  Paladin  Death Knight* 
Strength   +1  +3   +1    +1  +2  +88 
Agility   +3     +3     +53 
Stamina   +1  +2    +1  +1  +1  +2  +79 
Intellect  +2    +3  +2   +2  +1   +9 
Spirit  +3    +2  +2  +1  +2  +2  +1  +22 

*Death knight bonus stats represent a level 55 character.

Cataclysm racesWorld of Warcraft's next expansion pack, Cataclysm, will introduce worgen for the alliance and goblins for the horde.

"Subraces"Subraces (aka subspecies)[3] are generally considered lesser groups within a main race/species. However, even these subgroups are considered separate race or species themselves in some sources.

Dwarf subraces can include Wildhammer, Ironforge, or Dark Iron dwarves.[5]
The various types of trolls are usually considered separate subraces, though occasionally separate races.[6][7][8][5] The terms appear to be interchangeable to Blizzard.
Aesir and vanir are considered two of the titan's various subraces.[9]