Government is a group of people invested with the power to manage a political unit, organization or, more often, a State. It can take many forms, ranging from a monarchy or an oligarchy to a democracy (direct or representative) or an autocracy. Governments exist to provide security, protect property rights, foster literacy and numeracy, establish laws, collect taxes, and perform a host of other functions.
A central function of Government is to regulate access to common goods such as fish in the sea, wildlife, and public lands, which all may use without charge but are of limited supply. They must be protected to ensure that a few people do not take all that is available and leave others with nothing. Government also enables citizens to live together in peace by providing police, fire and postal services, as well as education and healthcare.
The Federal Government of the United States consists of three distinct branches: executive, legislative and judicial. Legislative authority is vested in Congress and the President, and the judicial branch is composed of the Supreme Court and lower federal courts. States and local governments are modeled after the Federal Government and generally have similar structures, including elected governors as chief executives, legislatures that are typically bicameral, with upper and lower houses that are usually called the Senate and House of Representatives, but whose name varies from one State to another.