The defining characteristic of a presidential government is how the executive is elected, but nearly all presidential systems share the following features.
- the president is both head of state and head of government.
- the president has no formal relationship with the legislature. He is not a voting member, nor can he introduce bills.
- the president has a fixed term of office. Elections are held at scheduled times, and cannot be triggered by a vote of confidence or other such parliamentary procedures.
- the executive branch is unipersonal. Members of the cabinet serve at the pleasure of the president and must carry out the policies of the executive and legislative branches.
Countries with congressional and presidential systems include the United States, Indonesia, the Philippines, Mexico, South Korea, and most countries in South America. The widespread use of presidentialism in the Americas has caused political scientists to dub the Americas as "the continent of presidentialism."