As defined by Max Weber (1864-1920), State is the institution which claims the exclusive right to the legitimate exercise of force in a given territory, through the use of police to enforce laws or the army to maintain civil stability. Max Weber's definition of a state as a polity that maintains a monopoly on the use of violence is widely used, as are many others. The concept of the nation-state, theoretically or ideally co-terminous with a "nation", became very popular by the 20th century in Europe, but occurred rarely elsewhere or at other times. Institutions of the state include government and agencies like the army, police, judiciary, crown corporations, welfare bureaucracies, and regulatory bodies.
States are the subjects of public international law, also known as the law of nations. Their existence and conduct is governed by treaties and customary rules. In British English, state is the only term that has that meaning, while the government instead refers to the ministers and officials who set the political policy for the territory, something that speakers of American English refer to as the administration.
A state is a set of institutions that possess the authority to make the rules that govern the people in one or more societies, having internal and external sovereignty over a definite territory. Some states are sovereign, while other states are subject to external sovereignty or hegemony, where supreme authority lies in another state. The term "state" also applies to federated states that are members of a federation, in which sovereignty is shared between member states and a federal body.
While there have been stateless societies, most complex societies have state systems of formal government and administrative bureaucracy.
In a federal system, the term state also refers to political units, not sovereign themselves, but subject to the authority of the larger state, or federal union, such as the "states" in the United States.
The Montevideo Convention of 1933 provides four criteria for achieving statehood: a permanent population, a defined territory, government and capacity to enter into relations with other states.
Speakers of American English often use the terms "state" and "government" as synonyms, with both words referring to an organized political group that exercises authority over a particular territory.
Small city-states have become rarer and comparatively less prominent in modern times. A number of them survive as federated states, like the present day German city-states, or as otherwise autonomous entities with limited sovereignty, like Hong Kong, Gibraltar and Ceuta. To some extent, urban secession, the creation of a new city-state, continues to be discussed in the early 21st century in cities such as London.