Parliament's primary role includes examining and approving new laws, starting with a proposed bill for either a new law or an amendment to an existing one. Bills can be introduced by the government or individual MPs, undergoing similar examination stages in both Houses but differing in rules and procedures. Changes made to bills must receive agreement from both Houses before becoming law; however, certain conditions allow Commons-passed bills to bypass Lords' approval. An Act of Parliament represents primary legislation that outlines key principles while enabling ministers to detail specifics through secondary legislation.