Law enforcement is any system by which some members of society act in an organized manner to enforce the law by discovering, deterring, rehabilitating, or punishing people who violate the rules and norms governing that society. Although the term may encompass entities such as courts and prisons, it is most frequently applied to those who directly engage in patrols or surveillance to dissuade and discover criminal activity, and those who investigate crimes and apprehend offenders, a task typically carried out by the police or another law enforcement agency. Furthermore, although law enforcement may be most concerned with the prevention and punishment of crimes, organizations exist to discourage a wide variety of non-criminal violations of rules and norms, effected through the imposition of less severe consequences.