The President of a country heads the executive branch, is commander in chief of the armed forces, and approves or vetoes laws passed by Congress, which can then be overridden with a two-thirds majority vote. The President also negotiates treaties and nominates the people who head executive departments, such as the CIA and the Environmental Protection Agency. In the United States, the President is required to address Congress each January on the state of the nation and his or her agenda for the coming year.

Unlike the monarchies of Europe, the President of the United States is a constitutionally elected position. The responsibilities of the office have expanded with America’s rise to superpower status in the twentieth century and its increased involvement in world affairs.

The word “president” can also refer to the presiding officer of any social organization, such as the presidents of Yale College and the rector of Oxford University. It is also a title for the presiding officials of unicameral legislatures and one or both houses of bicameral legislatures, in countries that use this form of government. The term is used in a few places for the head of a parliamentary system, as well: the chairman of a parliamentary body and, in China, the General Secretary of the Communist Party.