World of Warcraft, often referred to as WoW, is a massively multiplayer online role-playing game (MMORPG). It is Blizzard Entertainment's fourth released game set in the fantasy Warcraft universe, which was first introduced by Warcraft: Orcs & Humans in 1994. World of Warcraft takes place within the world of Azeroth, four years after the events at the conclusion of Blizzard's previous release, Warcraft III: The Frozen Throne. Blizzard Entertainment announced World of Warcraft on September 2, 2001. The game was released on November 23, 2004, celebrating the 10th anniversary of the Warcraft franchise. [source:wikipedia]