Criminal law is the body of law that relates to crime. It prescribes conduct perceived as threatening, harmful, or otherwise endangering to the property, health, safety, and welfare of people inclusive of one's self. Most criminal law is established by statute, which is to say that the laws are enacted by a legislature. Criminal law includes the punishment and rehabilitation of people who violate such laws.

Criminal law varies according to jurisdiction, and differs from civil law, where emphasis is more on dispute resolution and victim compensation, rather than on punishment or rehabilitation.

Criminal procedure is a formalized official activity that authenticates the fact of commission of a crime and authorizes punitive or rehabilitative treatment of the offender.

What Do People Who Work in Criminal Law Do?
Criminal lawyers apply criminal law to defend clients accused of a crime or hold those who have committed a crime accountable. Much of their work involves going to court to represent their various clients. When they’re not in court, they might research a case and the applicable law or communicate with their clients to update them about their next court appearance.