Bills are Acts in draft form. The Encyclopaedic Australian Legal Dictionary (Lexis+) provides a useful summary of Bills: 

• Commonwealth Bills require approval by the House of Representatives and the Senate, and assent by the Governor-General ('royal assent’) for enactment. State Bills require approval by the relevant houses (or house in Queensland) and the assent of the State Governor. Northern Territory Bills require approval by the Legislative Assembly and the Administrator or Governor-General, while Australian Capital Territory Bills require only the approval of the Legislative Assembly, although they may be disallowed by the Governor-General within six months.
• A Bill tabled before parliament may be amended extensively before enactment.
• A Bill is typically drafted in separate clauses, each of which can stand on its own, for the purposes of being debated in parliament. Generally, a court cannot resort to drafts of a Bill, whether introduced into parliament or not, when interpreting legislation.
• An exception is made for the drafts of the (CC) Commonwealth Constitution arising out of the Constitutional Conventions: Seamen's Union of Australia v Utah Development Co(1978) 144 CLR 120; 22 ALR 291. It is arguable that drafts of a Bill might constitute ‘other relevant documents' furnished before parliament, which may be used in the interpretation of legislation: for example (CTH) Acts Interpretation Act 1901 s 15AB; (NSW) Interpretation Act 1987 s 34(2)(e).

Every Bill has three readings in each House of Parliament. It is usually amended several times, before being given Royal Assent and becoming an Act.

One way to keep an eye on changes in different areas of law is to monitor the Bills that are before Parliament. 

Each Bill is accompanied by an explanatory statement, often referred to as an Explanatory Memorandum. This statement explains the content of the Bill, provision by provision.

To find out more about Bills, search this Bills Digests website, which provides a plain English summary of Bills and detail their purpose, background and main provisions (from Parliament of Australia).

This feed advises of recent Bill activity within the Western Australian parliament. You can also subscribe to email tracking of each new Bill in the WA Parliament.