<human>:  What are the differences between the American presidential system and the British parliamentary system?
<bot>: The American presidential system is based on separation of powers, where the legislative, executive, and judicial branches are separate institutions. The executive is directly elected by the people. The president leads the executive branch and his or her role is mainly focused on foreign policy and national security. The British parliamentary system, conversely, is based on separation of powers but the executive and legislative branches are intertwined. The Prime Minister leads the executive branch, and most power lies with the legislature. The Prime Minister is appointed by the monarch, usually from the party with majority support in the legislature. Additionally, the Prime Minister and cabinet are accountable to the legislature and have to constantly seek their approval.