The United States government is a federal system that operates under a Constitution, which outlines the structure and powers of government. It is divided into three branches: the Legislative, which makes laws; the Executive, which enforces laws; and the Judicial, which interprets laws. This separation of powers helps prevent any one branch from becoming too powerful. The government is also characterized by a system of checks and balances, ensuring that each branch can limit the powers of the others. The President leads the Executive branch, while the Congress comprises the Senate and House of Representatives, and the Supreme Court heads the Judicial branch.