Crimes are divided into three basic categories: (1) felonies, (2) misdemeanors, and (3) infractions. Felonies are the most serious offenses that lead to longer-term confinement. The basic rule is that any crime from which a person can serve a year or more in jail is a felony. Misdemeanors are less serious criminal offenses for which the person usually receives a fine or a jail term of less than a year. Finally, infractions are very petty crimes—generally at the local level—for which a person usually only has to pay a fine and not serve any jail time.

Many states further subdivide felonies and misdemeanors into different classes.