A law, known as an act or a statute, begins as a bill. A bill becomes a law only after Parliament has approved it. Members of Parliament may introduce bills in either the House of Commons or the Senate. There is only one exception - bills that involve raising or spending money (what are called money bills) must be introduced in the House of Commons. Government Bills are drafted by the Department of Justice, and Private Members' Bills are prepared with the assistance of the Legislative Council Office. In practice, most bills originate in the House of Commons.