The federal government of the United States is the centralized United States governmental body established by the United States Constitution. The federal government has three branches: the legislature, executive, and judiciary. Through a system of separation of powers or "checks and balances", each of these branches has some authority to act on its own, some authority to regulate the other two branches, and has some of its own authority, in turn, regulated by the other branches. The policies of the federal government have a broad impact on both the domestic and foreign affairs of the United States. In addition, the powers of the federal government as a whole are limited by the Constitution, which leaves a great deal of authority to the individual states.
