Thanks for your question, Ken. Senate estimates hearings, also known as estimates committees or simply 'estimates', allow senators to scrutinise—closely examine—how the executive government is spending taxpayers' money. You can find out more about estimates with the Senate estimates fact sheet.
If you want specific information about the most recent estimates, you can find it on the Australian Parliament House Senate estimates page. This page includes links to each of the committees and a searchable database of questions on notice.
If you’re after more detailed information on the Budget, you can also take a look at the Parliamentary Budget Office webpage.