The document summarizes the qualifications and roles of the U.S. presidency. To become president, one must be a natural born U.S. citizen at least 35 years old who has lived in the country for at least 14 years. The president has five main constitutional roles: head of state, chief executive, commander-in-chief, chief diplomat, and chief legislator. Additional powers have grown out of statutes and presidential practice over time. The vice president assumes the presidency if the president leaves office, and the cabinet serves as an advisory board to the president.