Police powers are granted to states in the 10th Amendment to the U.S. Constitution, which reserves to the states the rights and powers "not delegated to the United States," which include protection of the welfare, safety, health and even morals of the public. Police powers denotes the basis for many regulatory subjects, such as licensing, inspection, zoning, safety regulations, and working conditions as well as law enforcement. Police powers may be used, for example to detain people or search things like vehicle.
It is a general term that expresses the fundamental power vested in every state to limit and regulate the exercise of private rights in the interest of public health, public morals, public safety, and the general welfare of the community. Governments have exercised police power to prohibit the sale of liquor and cigarettes and gambling. Cities and towns have prohibited the making of bricks in a town, the maintenance of livery stables, public laundries, billboards, public garages, coal yards and slaughterhouses.