The currency market has long served an important function in global business by providing companies a way to exchange funds in one currency for funds in another. (sapling.com)
Over the rest of the trading day, the banks exchange funds amongst themselves depending on which institution happens to have a surplus of funds and which happens to have a deficit. (rba.gov.au)
If dealing with large currency value always best to check with winery / mint or distributor / bank before exchanging funds. (thedrinksbusiness.com)