I've seen some people get infracted for breaking a rule. What exactly is an infraction? Thanks in advance.

An infraction is a punishment for a violation of a rule.
The infraction system is a point system. If you accumulate too much points, you will get a ban. You will get an amount of points depending of your violation category.

I hope it cleared your ideas.

Think of its a warning. Once you get a build up of infractions. You get banned for a certain amount of time. First infraction ban is one day. Second is longer.

Great, I got exactly what I wanted to know. Thanks. ^^

some infractions are soo serious they never go away, such as my two permabans left me with 20 infractions for life