Draft bills are early versions of bills. The Government do not have to publish a bill in draft form, but they sometimes do to get feedback on what they are proposing. The process of examining a draft bill is known as pre-legislative scrutiny.
Pre-legislative scrutiny is often undertaken by specially-formed joint committees with members drawn from the House of Commons and the House of Lords. But it can also be undertaken by a select committee with a specific interest in the draft bill. Sometimes pre-legislative scrutiny is undertaken by both a joint committee and a select committee.