I've been here 16 years and I still don't really know. I leave all the money stuff to the Wife.
My understanding is that there's a state pension which is a pittance and is means tested on income and assets. So the richer you are when you retire the less you'll get.
Your employer pays money into a Super fund (Superannuation). That's a percentage of your salary and is compulsory. It's currently 11% and rises each year. So the higher your salary, the more you'll get. You can also voluntarily contribute more of your salary to your Super fund.
You can also contribute to your own private retirement fund.
@Eednud does that sound about right?