What makes a MMO different from a single player game?
Besides the fact that tens of thousands of people can play this type of game at the same time and interact with each other, the biggest difference is that MMORPGs can be constantly updated with new content and challenges for the player. In the case of Dark Age of Camelot, Mythic creates new content and improvements for the game on a regular basis. Throw in five retail expansions, and you have a game that since it was released in 2001, has increased dramatically in size, scope and features. This type of dedication to new content is what sets online games apart from single player games.