The Forex, and also known as "The Foreign Exchange" market exists wherever one currency is traded for another. It's the largest financial market in the world. Simply if we compare the New York Stock Exchange trades vs changing hands in forex, we will discover Forex market is a lot of times larger than both Equity and Treasury markets combined.
Forex or "Foreign Exchange" is where the money of one nation is traded with another. The most important and popular pairs of exchange in the forex market are "Euro Dollar", and you will see this pairs in all forex display screens as "EUR / USD". There are also a lot of others pairs but sure not important and not famous as "EUR / USD" pairs, like: –
1-The British Pound, and you will see this pairs in all forex display screens as "GBP / USD".
2- The Japanese Yen, and you will see this pairs in all forex display screens as "USD / JPY".
3- The Swiss Franc, and you will see this pairs in all forex display screens as "USD / CHF".
However there is a problem in the forex market until this day, there is no one central exchange where everyone can exchange the currency. All the currency traded are done over the telephone and online through a very big networks that connects all the banks, brokers and currency traders with each others.
Currency trading in the past was just for the banks, but today and after the new revolution electronic economy, online forex trading companies start to offer a lot of services to all traders around the world. Today if anyone have a computer and internet connection can easily start to trade currencies, but sure the experience and analysis is very important to success in forex game.