Community points are a virtual reward given to users for contributing something to the site. For example:

Forum report - 1 point
Band / album / video / trivia / logo edit - 1 point
Edit lyrics - 2 points
Add album / video / trivia / logo - 3 points
Add news / event - 4 points
Add review - 15 points
Add article / concert review - 20 points

When you have accumulated 100 points, you can create a custom title (edit it yourself in your profile) and suggest bands.

Community points can also be helpful when deciding whom to promote to Official Contributor, Elite, or Staff member.