Legislation is commonly referred to as Acts or Statutes, and includes delegated or subordinate legislation (used interchangeably) which is legislation made by government agencies under an Act. Law-making authority is conferred (delegated) by Parliament on its agents to produce this legislation which is made under (or subordinate to) an Act.
Before an Act is passed, it is presented to Parliament as a Bill (a draft form of legislation) before it is enacted. Explanatory Memoranda (or Notes or Statements) are issued with Bills to explain their purpose and individual provisions.
The materials produced prior to the enactment of an Act play their own unique role in legal research and can assist in the interpretation of legislation and often, in understanding the purpose of an Act. This 'pre-legislation' material is know as extrinsic material and includes parliamentary and law reform committee reports, Explanatory Memoranda (or Notes or Statements), and Second Reading Speeches.
Commonwealth extrinsic material: Sources outside of the Act itself which can be used to help interpret meaning or intention, are set out in the Acts Interpretation Act 1901 (Cth), s 15AB(2).
States and Territories extrinsic material: The State Interpretation Acts all have similar provisions, except for the South Australian Act. However, there is South Australian Supreme Court authority to suggest that notice will be taken of extrinsic material when interpreting legislation: R v Owen (1996) 66 SASR 251.
(Jay Sanderson and Kim Kelly (eds), A Practical Guide to Legal Research (Lawbook, 4th ed, 2017).