It is basically... your reputation
It's affected by how other people judge you by what you post. If you get over 100 posts, you also get the chance to give people reputation, or take away reputation.
If you are helpful or nice or simply please somebody, you might get reputation, but if you're naughty and start spamming your reputation goes down
Or, it could also be used for say, link exchanges and you don't honor the deal or if you scam somebody, or give people a great deal. Like it says, it's reputation XD
