What is traded on the Foreign Exchange market

The simple answer is money. Forex trading is the simultaneous buying of one currency and the selling of another. Currencies are traded through a broker or dealer, and are traded in pairs; for example the euro and the US dollar (EUR/USD) or the British pound and the Japanese Yen (GBP/JPY).

Because you're not buying anything physical, this kind of trading can be confusing. Think of buying a currency as buying a share in a particular country. When you buy, say, Japanese Yen, you are in effect buying a share in the Japanese economy, as the price of the currency is a direct reflection of what the market thinks about the current and future health of the Japanese economy.