A penal code can be defined as that portion of a state's laws that deal with defining the elements of particular crimes and specifying the punishment for each crime. Other parts of the laws of a given state can also define crimes and punishments, such as a traffic code or a building safety code, or laws addressing environmental resources by regulating hunting, fishing, or forestry.
In many states, the body of criminal law is published in one or more printed books for convenient reference by lawyers, other professionals of the criminal justice system, and, in principle, ordinary citizens.