Forex trading is typically done through a broker or market maker. As a forex trader you can choose a currency pair that you expect to change in value and place a trade accordingly. For example, if you had purchased 1,000 Euros in January of 2005, it would have cost you around $1,200 USD. Throughout 2005 the Euro’s value vs. the U.S. Dollar’s value increased. At the end of the year 1,000 Euros was worth $1,300 U.S. Dollars. If you had chosen to end your trade at that point, you would have a $100 gain.