How does elo work?

http://www.elometer.net/

Okay so I have played chess for a while but never rated and I would like to know how elo works... I took this test but I don't trust the results.

Is a rating system within a group. The better the group the lower your elo.

The mathematical explanation:
FAQ

Rough summary:
Ratings are relative to other players. The number means nothing by itself. An RHP rating tells you if you are better, or worse, than other RHP players. Means nothing outside RHP.

Originally posted by BigDoggProblem
The mathematical explanation:
FAQ

Rough summary:
Ratings are relative to other players. The number means nothing by itself. An RHP rating tells you if you are better, or worse, than other RHP players. Means nothing outside RHP.

Originally posted by Ashiitaka
Okay that makes sense because I scored 1900 on that test but I'm nowhere near as good as 1900 players on here are, so I was confused. It makes more sense that it is ony relevant to RHP.

Originally posted by sonhouse
What test are you talking about?