The U.S. dollar is the currency most used in international transactions. Several countries use the U.S. dollar as their official currency, and many others allow it to be used in a de facto capacity. It's known locally as a buck or greenback.
The dollar has been the currency of Canada since 1858. A number of central banks keep Canadian dollars as a reserve currency. It's known locally as a buck or a loonie, with the two-dollar coin known as a toonie.
