What is the difference between the House of Commons and the House of Lords?

The UK Parliament operates a two-House system. Both Houses make laws, check the work of the government and debate issues.
The Commons consists of 650 MPs (Members of Parliament) who are elected by the public. Each MP represents one constituency (a small part of the country). The Prime Minister and members of the government's opposition work in the Commons. The Commons alone is responsible for making decisions about money, like new tax laws.
The Lords is the second chamber of Parliament. It is made up of about 780 members who are not elected. Some people inherit their status of Lord from their family (about 92 members of the Lords). Others are chosen specifically by the Prime Minister because they are experts in their field.