Forex involves the trading of currencies. It is the largest financial market in the world and has an estimated daily turnover of 1.9 trillion dollars. This turnover is larger than all the worlds stock market on any given day.
The forex market does not have a fixed exchange. The forex market is considered an over-the-counter (OTC) market. The forex market is completely electronic and trades are executed over the phone or on the Internet. Until 10 years ago the forex market was the preserve of large financial institutions. Now an ever-increasing amount of individual traders thanks to the advent of the Internet and an increasing amount of online forex brokers are trading forex.
Currencies are always traded in pairs. A typical pair would be EUR/USD (Euro over US dollars). The first currency is the base. The second currency is the counter currency. The pair can be viewed, as the amount of the secondary currency that is needed to buy 1 unit of the first currency. If you were to buy the above pair you would buy Euro and simultaneously selling US dollars. If the pair were sold the reverse would happen you would sell the Euro and buy the US dollar. This might sound...