What that this MMORPG? (eng. Massively-Multiplayer Online Role Playing Game) - its genre of computer games, where large number of players is meeting in virtual world. It's simple definition. Like in games RPG (Role Playing Game) player is creating avatar and control this avatar in virtual world. Simple. Some of games here are for free (cool) but some are only for subscribed players (yeah you must pay, month after month or buy special life time subscription for around 200 Euro).

Ok some I've got this character avatar and then what?

You are making quests, you can beat monsters, travel here or there. Your character - avatar has levels of experience. You must gather them specific amount to level up your character. On the start of the game you've got first level. It's depend which here exactly game you are playing, how many levels you've got to get. In World of Warcraft max level is now 70 but after premier of expansion Wrath of the Lich King, this experience cap will be raised to 80 level. Cool isn't?

Yeah but what so cool about getting points??I don't like numbers.

Lol. All fun is to play with other mates in this virtual world. You are free, you can do what you want. But really you should try it. It's really great fun.

Ok but I spend money and then I'm gonna resign, and I'm out of money. What then?

Look for free trials. Each popular MMORPG has free trials! You can play with other players for absolutely NOTHING. Just download game, create account and you can travel to world of fantasy! Lord of the Rings, World of Warcraft, City of Heroes/Villains or other games are available. Just check details. I discover Lord of the Rings Online in such way, I wasn't sure what kind of game it was and I download it. Later I bought it and I was really excited. Everyone can play online in free games this is really cool thing. Everyone like this genre and can free play in trials of most popular games of that type. You can try them all. Just download them.