i joined yesterday and i was just wondering what it meant , thanks.
It's a score based on overall member approval or disapproval of the posts you make here. Anytime a member "thanks" a post you make, you get one point. Or, members can choose to use the Rep button (looks like +R- on the row of buttons) to approve or disapprove of a post and leave a comment as to why. Approval in this manner yields more points, and a disapproval can take away points.
Rep scores should be looked at as a fun way for members to pat each other on the back. They should not be taken too seriously.