The money is rolled into a fund and you can benefit from it only from 65 yearsof age if you are a citizen or permanent resident. Be careful if you work for various employees over several years, make sure your money goes into only one fund (otherwise it will be spread across funds and you will pay fees for each fund).
For the non- permanent resident who has worked temporarily Australia and is leaving for good, you may be able to recuperate your contributions. Go to http://www.ato.gov.au/super for more information.