A state is an organized political community living under a single system of government. Speakers of American English often use state and government as synonyms, with both words referring to an organized political group that exercises authority over a particular territory. States may or may not be sovereign. For instance, federated states that are members of a federal union have only partial sovereignty, but are, nonetheless, states. Some states are subject to external sovereignty or hegemony where ultimate sovereignty lies in another state. The term "state" can also refer to the secular branches of government within a state, often as a manner of contrasting them with churches and civilian institutions.