On the front page of the site it says GAIA Online: A Roleplaying Community
Sure it has many other functions, but Roleplaying Community is apparently how it is defined
Gaia means world in some language. so Gaia online is almost a universe, bebause it is a forum with all the NPC's and those things. It is a story, a forum, and you can also e-mail here but that isnt the most important thing.