<human>:  In the Constitution of the United Kingdom, what is the difference between the House of Commons and the House of Lords?
<bot>: The House of Commons is elected by the people, and the House of Lords is appointed by the king. The House of Commons is made up of members of parliament, who are elected every five years. The House of Lords is made up of the oldest hereditary peers, who are appointed by the monarch. The House of Commons is made up of 650 members, and the House of Lords has over 800 members.