The Parliament makes laws about how federal money is spent. A government department might suggest an idea for a law (a bill) or advise its minister about a specific problem that exists but the Parliament is responsible for law-making.
Government departments assist ministers in developing government policy and implementing laws. Ministers work with their department, community organisations and professional associations to prepare new laws and change existing laws which need updating or improving. If the bill becomes a law, the minister and their department are responsible for putting the law into action.
Sometimes the Parliament gives the power to make decisions about the details of these laws to the relevant minister, executive office-holder or government department. This is called delegated law because the power has been delegated to that person or department. The Parliament holds the right to overrule these delegated decisions if it does not agree with them.