It means you have 0 infractions active out of 1 total. The infraction you've had was 2 points, so you got it for either useless post or ignoring rules. If enough points build up from active infractions - you will be banned.
You get infractions for doing something against forum policy, like making useless posts, or advertising in someone's thread, or bumping ancient thread for no good reason. Generally if you follow common sense you shouldn't get in trouble.