The Foreign Exchange market is the largest financial market in the world. Forex trading (trading on the foreign exchange market) is where you will buy one currency and sell another, or it may be a combination of a few different currencies in total. Trading involves matching one currency against another for example; you buy the Euro hoping it will rise against the U.S. Dollar. This also means you hope the U.S. Dollar will fall against the value of the Euro so that a profit can be made. You are trading using economic information about the two currencies. This can be done between any existing currencies available. This form of trading is considereds peculation.
A broker is still necessary to trade just as on other markets but unlike other markets most Forex brokers do not charge commission for trades. This is not to say they aren’t getting paid for their work, they manage to recover their expenses and profit on all your trades, by picking up the spread between the two currencies you trade. The spread is the difference between the bids and ask prices of the two currencies. The broker will open an account for you to make your trades. The amount of deposit can vary depending on the broker used. If your broker sets a margin at 3-5%, and you want to open a trade for $10,000 you would need to have on deposit $300-$500.
Forex trading is typically done using a margin. This is done by leaving a small deposit with your broker and which can be traded many times for the value of your deposit. For example, if you want to open a trade matching two currencies and you want to trade for $5,000. You make a deposit of $50 with the broker, and stand to gain much more than the $50 after you close the trade. You may also lose on the trade, but your losses, would be no more than your deposit if you take the necessary precautions to exit the trade once you reached your margin.