The Monarchy and Parliament
The UK is a constitutional monarchy. This means the King or Queen is the head of state, but their role is largely ceremonial. The current monarch is King Charles III, who succeeded his mother Queen Elizabeth II in September 2022.
The UK Parliament has two chambers: the House of Commons and the House of Lords. The House of Commons has 650 elected members, called Members of Parliament (MPs). The party with the most MPs usually forms the government, and its leader becomes the Prime Minister.
The House of Lords is made up of unelected members called peers. Most are appointed by the monarch on the advice of the Prime Minister. Some are senior bishops of the Church of England (the Lords Spiritual), and a small number are hereditary peers. The Lords scrutinises and revises legislation passed by the Commons but generally cannot block it.
The Prime Minister leads the government, chooses the members of the Cabinet (senior ministers), and appoints government departments. The Prime Minister's official residence is 10 Downing Street in London. The leader of the largest party not in government is the Leader of the Opposition.