

A student must understand each of the conditions and should never breach any visa condition.
You cannot work until you have commenced your course in Australia.
Once your course has commenced you are permitted to work a maximum of 40 hours per fortnight when your course is in session, and unlimited hours when your course is out of session.
Work that is formally registered as part of your course is not included in the 40 hours per fortnight limitation.
If you are a postgraduate research student who has commenced your masters by research or doctoral degree in Australia, there is no limit on the number of hours you may work.
Info Source: Australian Government - Department of Home Affairs