The Constitution provides a separation of powers in three branches:
1. Legislative - responsable of making laws.
It includes the Congress (Senate and the House of Reprensentatives) and special agencies and office that serve the Congress. The Legislative branch has the power to draft proposed laws, declare war and confirm or reject presidential nominations of federal agencies, judges and the Supreme Court.
2. Executive - responsable of carring out the law.
It includes the President, Vicepresident and the Cabinet, among others. The first has the power to veto bills enacted by Congress or to sign legislation into law. This branch conducts diplomacy with other nations, and the President has the power to negotiate and sign treaties, with the two-third ratification of the Congress.
3. Judicial - interprets the law.
It includes the Supreme Court and Federal Courts and Judicial Agencies. It has the power to apply the law in individual cases and decides if a law violates the Constitution (Judicial Review).