The President of the United States of America has two primary responsibilities. He is the head of the executive branch of the federal government and commander in chief of the armed forces.

As head of the federal government, the president takes overall responsibility for the day-to-day governance of the country. To this end, he appoints a cabinet, including secretaries of state, treasury, defense, and various other departments. With the single exception of the vice president, the president can fire and replace any member of the cabinet and is ultimately responsible for all their decisions. As commander in chief, the president can deploy the armed forces, though he needs congressional approval to do so.

The president has a few specific duties, such as the State of the Union address. Beyond these, there is nothing he has to do, but many things he can do. Certain presidents, such as Bill Clinton, have a reputation for getting deeply involved in the details of government. Others prefer a more hands-off approach. The president is sometimes described as "the most powerful person in the world," but this is a highly subjective matter. Unlike the leaders of many countries, such as China and Russia, the President of the United States is subject to the law. The Constitution clearly intends that the president should be a citizen-legislator, without anything resembling royal or dictatorial power. The power of the president also depends to a great extent on whether his party is in control of the Congress.