World of Warcraft, often referred to as WoW, is a massively multi-player online role-playing game created by Blizzard Entertainment. World of Warcraft is the forth installment of the Warcraft Universe, this series was first introduced by Warcraft: Orcs and Humans in 1994. It takes place in a magical world of Azeroth, approximately fours years after Warcraft 3: The Frozen Thrones was released. Blizzard announced World of Warcraft at Blizz Con on September 2, 2001. The game was released on November 24, 2004, on Blizzard Entertainments 10th year anniversary.