Well a massive multilayer online role playing game is a game where millions (or thousands or hundreds of thousands for the smaller games) play online together in a virtual world. Different games have different settings and themes. They have close communities, actual economies, people of literally all ages (most people playing are between the ages of 20-45 but all ages from 13 and up play), and other cool stuff. You get to make close friends with people who never need to know your real name. There is absolutely no way for them to find out who you are or where your from unless you tell them so its easy to make friends and trust people..
There are a bunch of different types but Final Fantasy XI is probably the best option for someone past 20 because its mostly adults and is a more mature game. There is a free trial at
http://finalfantasyxi.com/ if you want to check it out.. Give it a try youll like it.
There is really no game like final fantasy XI but if you wanted to check out other massive multiplayer games as well (if your interested), there are a bunch.
World of Warcraft: More aimed at pre teens and teenagers but has the pro of being very easy. im not sure if you would like this but there is free trial as well:
https://signup.worldofwarcraft.com/tria ... blade25_01 : or
http://www.worldofwarcraft.com/index.xmlAion: I have never played this one nor do i know anyone who has since its new:
http://us.ncsoft.com/en/aion/There are more as well, just search 'top mmorpg' in google and your sure to find some good ones.