Australia’s safety laws for drones or remotely piloted aircraft (RPA) generally depend on whether the operator is flying commercially or recreationally.
If you are flying for any economic gain you need certification unless your RPA weighs less than two kilograms. Under these circumstances, you need to notify CASA and follow the standard operating conditions (SOCs). There are also reduced regulatory requirements for some private landowners/leaseholders operating RPAs.
If you are flying for fun and not any economic gain, then the regulations are less restrictive. You do not need to be certified, providing you follow some simple safety rules.
Whatever your reason for flying, it is an offence to operate an unmanned aircraft in a way that creates a hazard to another aircraft, another person or property.
Full information and downloadable apps can be found here
Information from the Civil Aviation Safety Authority website