The United Kingdom follows a parliamentary system of government, where the executive power is exercised by the prime minister and the cabinet. The prime minister is usually the leader of the political party that holds the majority in the House of Commons. After a general election, the monarch invites the leader of the party with the most seats in the House of Commons to form a government, and that individual becomes the prime minister.
Citizens of the UK directly vote for their preferred candidates in their respective constituencies during general elections. The candidates are nominated by political parties or can stand as independents. The candidate who receives the most votes in each constituency is elected as a Member of Parliament (MP) and takes a seat in the House of Commons. The political party or coalition with the majority of seats in the House of Commons is able to form the government, and its leader becomes the prime minister.
It is essential to note that while the prime minister holds significant power and influence in the UK government, the country's constitutional monarchy ensures that the monarch formally exercises various executive powers, such as dissolving Parliament and appointing the prime minister.