The United States government is built on a simple but powerful idea: no single person or body should hold all the power. To prevent that, the Constitution divides the federal government into three branches, each with its own role and its own checks on the others.
The Legislative Branch
Congress — the House of Representatives and the Senate — writes the laws, controls federal spending, and represents the people and the states. It is the branch closest to the voters, with House members elected every two years.
The Executive Branch
The President and the federal agencies carry out and enforce the laws Congress passes. The executive branch also conducts foreign policy and commands the armed forces, all within limits set by the Constitution and the courts.
The Judicial Branch
The courts interpret the laws and decide whether they are being applied consistently with the Constitution. Through judicial review, the Supreme Court can strike down laws or actions that violate the nation's founding charter.
Checks and balances: each branch can limit the others — Congress can override a veto, the President appoints judges, and the courts can rule actions unconstitutional.