The Australian currency is denoted in dollars and cents.
"All notes are sized according to their denomination for the visually impaired. They are the same height but different lengths, in order of their value ($5 being the smallest, $100 the largest).
Because of the aim to be cutting edge, counterfeits are rare and there are easy ways of checking. All Australian bank notes have a clear plastic "window" in the bottom right-hand corner of the note, and the larger denominations ($20, $50 and $100) have the value embossed on to this. Every note also has a seven-pointed star which has only half the printing on each side - hold it up to the light to see that it is genuine." (tripadvisor.com)
One Australian Dollar (AUD) = 100 cents
● Bill denominations are: $5, $10, $20, $50, $100
● Coin denominations: 5c, 10c, 20c, 50c, $1, $2
All major Credit cards are accepted in Australia but you will want to have local currency for smaller shops or restaurants, taxis and drinks in pubs. There may be minimum purchase amounts in smaller stores, in order to use a credit card.
Using your Bank ATM card will usually give you the best exchange rate. It allows you to withdrawal in local currency. You will want to check with your own Bank to see what Branch in Australia they may have a banking relationship with to save on ATM fees and exchange fees.
For example Bank of America has a bank partnership called Global ATM Alliance. By using the WestPac Bank to withdrawal money in AUD there is no ATM fee or international transaction fee.
To easily convert your USD into AUD, use the XE Converter. You may want to down load the app to your smartphone.