A crime can be either a felony or a misdemeanor.
A felony is a more serious crime than a misdemeanor. Shoplifting, for instance, is usually a misdemeanor, but can be a felony depending on what was stolen and whether or not the shoplifter already has a criminal record.
Shoplifting guns would be a felony, while shoplifting bubble gum would be a misdemeanor. A felony stays on your criminal record and you may be asked by colleges or employers to report any felony crimes of which you have been convicted. Misdemeanors do not usually appear in your permanent record.