<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 monarch. The House of Commons is the lower house of the Parliament of the United Kingdom, while the House of Lords is the upper house of the Parliament of the United Kingdom. The House of Commons is made up of 650 members, while the House of Lords has only 708 members. The House of Lords has a lot of power, and can block laws passed by the House of Commons.