Currency exchange business in physical, allow you to exchange one country's currency for another by executing buy and sell transactions. For example, if you have U.S. dollars and you want to exchange them for Australian dollars, you would bring your U.S. dollars (or bank card) to the currency exchange store and buy Australian dollars with them. The amount you would be able to purchase would be dependent on the international spot rate, which is basically a daily changing value set by a network of banks that trade currencies.