Native Title Act 1993 (Cth) was implemented in response to the Mabo Case where the notion of
Terra Nullius was found to be wrong, and thus, overturned.
Mabo case was
NOT about Aboriginals but Torres Strait Islanders who were trying to claim back native title. The basic difference between Aboriginals and Torres Strait Islanders (TSI) is that TSI occupied land and was passed down from generation to generation. Restrictions included the necessary proof of ownership and that land could only be claimed if it was owned by the Crown. (crownland and not leaseland)
The Wik Decision, a separate case, decided that the land could be shared (or coexist) by both a mining company and the Wik people even though it was lease land.
The Native Title Amendment Act was then legislated in respinse to the Wik Decision, providing restrictions on the grounds of claiming land. (similar to the 20 allowable matters clause in the
Workplace Relations Act 1996 (Cth).
My memory of this is very vauge, i hope it didn't confuse you more