A proposed new law or changed law is discussed in Cabinet. Often people of Australia put pressure on the government to change something.
If the government decides to proceed, government lawyers are asked to draft a bill. A Bill is basically a 'first draft' of an Act of Parliament.
Copies of the bill are given to all members of the House of Representatives to read in their own time.
Then the bill goes through a second reading process where they propose the likely benefits of the bill. The bill then undergoes a third reading in the lower house then if it passes a vote it gets given to the Senate.
The Senate goes through the same process as the House of Reps did in steps 3 to 4. If the bill is refused they can make changes but must be approved by the House of Reps again before it can be passed fully and become law. If they approve of the Bill it is sent to the Governor General for his Royal Assent.
If the Governor General approves and signs the bill it becomes an act of Parliament. It is proclaimed and legally binding for all Australian Citizens.