No, that's not the real Australian flag.
Here's a pub fact for you - the study of flags is called vexillology.
Unless you're really, REALLY well travelled, a good number of these flags might be unfamiliar - which is exactly why we've chosen them. As far as we've been able to ascertain, all of these flags are currently in use by their respective country.
We've picked out eighteen flags in total, and all you've got to do is match them to their respective country.
Good luck!