The game worlds are separated by "servers", which are typically in reference to the computer server clusters that make up each game world. These are systems maintained by Blizzard Entertainment and are partially paid for by the player monthly subscription fee.
Starting at level 1, the game is designed to quickly provide players with a set of small goals, thus familiarizing themselves with the game world. These goals, or "quests", are typically tasks provided by computer-generated "NPCs" or "Non-Player Characters" and typically involve fighting and defeating other NPC antagonists or collecting and delivering certain items. Through this progression players obtain new abilities and equipment, eventually teaming up with others to fight and defeat increasingly difficult encounters.
The World of Warcraft game environment also allows players to engage and combat other players from the opposing "team" under certain rules and controlled circumstances depending on the type of ruleset the game server is running. This is referred to as "PVP" (Player Versus Player). There are currently 4 different types of game rulesets:
1) PVE: Player-Versu...