1. The legislative branch, consisting of the United States Congress, which is made up of the Senate and the House of Representatives. The legislative branch's primary responsibilities are to create laws, pass budgets, and declare war.
2. The executive branch, consisting of the President of the United States, the Vice President, and the various federal departments and agencies. The executive branch's primary responsibilities are to implement and enforce the laws created by the legislative branch, as well as to conduct foreign policy and serve as the commander-in-chief of the armed forces.
3. The judicial branch, consisting of the Supreme Court of the United States and the lower federal courts. The judicial branch's primary responsibility is to interpret the laws created by the legislative branch and to determine their constitutionality.