Forex is one of the largest markets in the world and add to that the reasons for its growth are many which also include the potential for higher market movements and economic trend which affect the economy to a macro scale.
The trade of Forex basically involves purchase of one currency relative to another. Thus there is always a pair of currency which is involved in the deal. It is basically known as trading or foreign exchange. At times it is also known as currency trading. This is one such global market which is also the biggest on in the world.