Definition: Exchange rate is the price of one currency in terms of another currency. Description: Exchange rates can be either fixed or floating. Fixed exchange rates are decided by central banks of a country whereas floating exchange rates are decided by the mechanism of market demand and supply What Is The Exchange Rate Today? Whether you want to transfer euros to dollars or loonies to rupees, this is the place to check live and historical currency exchange rates. With these tools, you can time your transfer, so your international payments go further.