The main job of the High Court of Australia is to interpret the Australian Constitution and to settle disputes about its meaning. The High Court has the power to consider federal (national) legislation (laws), and decide whether according to the Constitution the federal Parliament had the power to make that law. The High Court can invalidate (cancel) any legislation or parts of legislation that it finds to be unconstitutional.
Interpretations of the Constitution by the High Court have evolved over time. To find out more you might like to look at our Closer Look paper about The Australian Constitution.