The modern foreign exchange market began forming during the 1970s. This followed three decades of government restrictions on foreign exchange transactions under the Bretton Woods system of monetary management, which set out the rules for commercial and financial relations among the world's major industrial states after World War II. Countries gradually switched to floating exchange rates from the previous exchange rate regime, which remained fixed per the Bretton Woods system.
Forex is a portmanteau of foreign currency and exchange. Foreign exchange is the process of changing one currency into another currency for a variety of reasons, usually for commerce, trading, or tourism. According to a recent triennial report from the Bank for International Settlements (a global bank for national central banks), the average was more than $5.1 trillion in daily forex trading volume.