As they already said MMORPG stands for Massive Multiplayer Online Role-Playing Games. It is an evolution of the Role-Playing Games genre also known as RPGs. In RPGs the player takes control of a character in a virtual world where he can go on a quest to do something great, be evil or good, develope his abilities and so on. By taking the player's character online to interact with many many other player characters the MMORPGs expand the wolrd in which the player ventures. The original idea was to have many many characters online that would act as real world people, albeit in alternative universe. Still it is not just like that because of many factors, one of them being the players not acting accordingly to the world.