What is traded on the foreign exchange market?

What is traded on the foreign exchange market?
The simple answer is money. Forex trading is the simultaneous buying of one currency and selling another. Currencies are traded through a broker or dealer, and are traded in pairs, for example the euro and U.S. dollar (EUR / USD) or the British pound and Japanese Yen (GBP / JPY).
Because you're not buying anything physical, this kind of trade can be confusing. Consider buying a currency as buying a stake in a particular country. When you buy, say, Japanese Yen, which are in effect buying a share in the Japanese economy because the price of currency is a direct reflection of what the market thinks about the current and future health of the Japanese economy.