The police are a constituted body of persons empowered by a state to enforce the law, to protect the lives, liberty and possessions of citizens, and to prevent crime and civil disorder. Their powers include the power of arrest and the legitimized use of force. The term is most commonly associated with the police forces of a sovereign state that are authorized to exercise the police power of that state within a defined legal or territorial area of responsibility. Police forces are often defined as being separate from the military and other organizations involved in the defense of the state against foreign aggressors; however, gendarmerie are military units charged with civil policing. Police forces are usually public sector services, funded through taxes.