The Australian Constitution gives the Governor-General executive power. This means that the Governor-General has been given certain powers to act on behalf of the Queen. However, the role of the Governor-General is not just defined by the Constitution, but also by custom and tradition.
While executive power is exercised by the Governor-General, in reality this is normally done on the advice of the Prime Minister and ministers, who have day-to-day responsibility for governing Australia. However, they regularly inform the Governor-General about this work.