Hardcore - Someone who's life is the game. They are always logged in, always doing the hardest content, has the crazy amount of achievements and the best gear.

Casual Hardcore - Your people who play only at certain times, but when they do play they go "balls to the wall". They are hardcore only some of the time.

Elitist - People who's attitude is about being the best and only if your the best can you accomplish what you need to do. Often confused with hardcore, but hardcore don't thrive to excluded people the way elitist do.

Casual - The people who are just passing the time. They might enjoy progression but rarely have the time to do it.

Newbie - someone new to the game, but willing to learn.

NOOB - someone who just doesn't want to learn, or someone who is a completely ignorant.