Ok, as of today as far as I know there is no single traded world wide recognized solo currency. And, I could also be wrong, world banks are simply transfer houses for currency exchange. So, you can use the US dollar in the US or the British Sterling Pound in the UK (also the Euro note in all EU nations). Each country runs on their own currency trading system. So if you are from Canada, which their note is called the Loon, and you wish to buy fruit in Japan, you will need to get your Loon exchanged to Yen. Otherwise, that poor Japanese fruit vendor will look at the Queens ugly mug in confusion as you Loon your way out of a peach.
