Government is a system of social control which grants a particular group of society the right to make laws, and the right to enforce them. There are many classifications of government, distinguished by whether power is held by one man, a few, or a majority, or on the basis of institutional organization and the degree of control exercised over the society.
Organizationally, governments may be classified into parliamentary or presidential systems, depending on the relationship between executive and legislature. Government may also be classified according to the distribution of power at different levels. It may be unitary—i.e., with the central government controlling local affairs—or it may be federated or confederated, according to the degree of autonomy of local government. A constitution is the primary law determining the form of government. It may be written, as in the United States, or largely unwritten, as in Great Britain. The traditional duties of government are providing internal and external security, order, and justice. Government's role today has expanded to include welfare services, regulating the economy, and establishing educational systems.
The U.S. federal government consists of three branches; the executive branch, legislkative branch, and judicial branch. The legislative branch of the federal government consists of the Congress, which is divided into two chambers -- the Senate and the House of Representatives. The judicial branch hears cases that challenge or require interpretation of the legislation passed by Congress and signed by the President. The power of the executive branch is vested in the President, who also serves as Commander in Chief of the Armed Forces.
