Class A Misdemeanor
Maximum jail time: Up to one year in jail (either a county or city jail)
Maximum fine: Up to $2,000
Class B Misdemeanor
Maximum jail time: Up to six months in jail (either a county or city jail)
Maximum fine: Up to $1,000
Class C Misdemeanor
Maximum jail time: Up to three months in jail (either a county or city jail)
Maximum fine: No specified maximum (fines are uncommon Class C misdemeanors in Alabama)
What does it mean?
Basically it means that if you are sentenced of any of these misdemeanors in Alabama you won't serve more than the max time listed here. In fact, in general you will serve less time because the jail may release you early on good behavior or the judge might actually specify less jail time during sentencing.
Concurrent or consecutive?
This is the big question - if you have multiple charges, does the judge specifically say that they are to be served consecutively? If so then you will do the sum of all time from all charges - so if you receive two Class A misdemeanors with 1 year each and they are run consecutively, you will serve 2 years in jail.
If the judge doesn't specify that the sentences are to run consecutive they will run concurrent, meaning you serve each of your sentences at the same time. Using the above scenario, if you are sentenced to serve 1 year each on two Class A misdmeanors, you will actually only serve one year in jail.