There are two kinds of discrimination that are against the law, direct and indirect discrimination.
Direct discrimination is when you are treated unfairly because of a characteristic you have, or you are assumed to have, that is protected by New South Wales law. For example, a real estate agent tells an Aboriginal person they have no properties for rent but tells a Caucasian person that they do, this may be direct discrimination.
Indirect discrimination is when there is a rule or requirement that is the same for everyone but unfairly affects people who have one of the characterstics protected by New South Wales law. For example, an employer has a policy that people need to be 180cm or taller to do a certain job, which could indirectly discriminate against women and some ethnic groups (sex or race discrimination).
Another exampl is a qualifying body excluding everyone with diabetes from registration for safety reasons, which could indirectly discriminate against individuals whose diabetes is controlled and would not impede them from doing the job safely (disability discrimination).