Foreign exchange market

The foreign exchange market (forex, FX, or currency market) is a worldwide decentralized over-the-counter financial market for the trading of currencies. Financial centers around the world function as anchors of trading between a wide range of different types of buyers and sellers around the clock, with the exception of weekends.
The purpose of the foreign exchange market is to assist international trade and investment. The foreign exchange market allows businesses to convert one currency to another. For example, it permits a U.S. business to import European goods and pay Euros, even though the business's income is in U.S. dollars. Some experts, however, believe that the unchecked speculative movement of currencies by large financial institutions such as hedge funds impedes the markets from correcting global current account imbalances. This carry trade may also lead to loss of competitiveness in some countries. [1]
In a typical foreign exchange transaction a party purchases a quantity of one currency by paying a quantity of another currency. The modern foreign exchange market started forming during the 1970s when countries gradually switched to floating exchange rates from the previous exchange rate regime, which remained fixed as per the Bretton Woods system.
The foreign exchange market is unique because of
trading volume resulting in market liquidity
geographical dispersion
continuous operation: 24 hours a day except weekends, i.e. trading from 20:15 UTC on Sunday until 22:00 UTC Friday
the variety of factors that affect exchange rates
the low margins of relative profit compared with other markets of fixed income
the use of leverage to enhance profit margins with respect to account size