Federal government of the United States
The U.S. federal government is composed of three distinct branches: legislative, executive, and judicial, whose powers are vested by the U.S. Constitution in the Congress, the president, and the federal courts, respectively. The powers and duties of these branches are further defined by acts of Congress, including the creation of executive departments and courts subordinate to the U.S. Supreme Court.
In the federal division of power, the federal government shares sovereignty with each of the 50 states in their respective territories. U.S. law recognizes Indigenous tribes as possessing sovereign powers, while being subject to federal jurisdiction. Provided by Wikipedia