You get an infraction for doing something wrong or breaking a rule(s). Infractions give you infractions points, the amount is dependent on the rule you broke. Receive five infraction points and you get a ban and so on.
the length of the ban is determined by the number of infraction points you have.
so lets say you violated a market rule and received a three point infraction, no problem. But then you receive a two point infraction for spamming, you get a day long ban (possibly longer, I don't remember.)
Infractions are set to expire after x amount of time, it's usually one or two months. After an infraction expires it's no longer valid and the points don't count toward your ban/punishment.
I.e. you break a rule and you get three points, a few months later it expires and you receive a 2 point infraction, you receive no ban.