Foreign exchange is a payment voucher expressed in foreign currency for international settlement. The International Monetary Fund's interpretation of foreign exchange is that foreign exchange is a creditor's right held by monetary management authorities (central bank, monetary institutions, foreign exchange stabilization fund and Ministry of Finance) in the form of bank deposits, treasury bonds and long-term and short-term government securities. Can be used when the balance of payments is in deficit. Including: foreign currency, foreign currency deposits, foreign currency securities (government bonds, treasury bonds, corporate bonds, stocks, etc.). ) and foreign currency payment vouchers (bills, bank deposit vouchers, postal savings vouchers, etc.). ).

Foreign exchange investment refers to the exchange of different currencies by investors in order to obtain investment income. Foreign exchange is the abbreviation of "international exchange", which has both dynamic and static meanings. The meaning of dynamics refers to a special commercial activity of converting one country's currency into another country's currency to pay off international creditor's rights and debts. Static refers to foreign currency that can be used for international settlement and assets expressed in foreign currency. The term "foreign exchange" usually refers to its static meaning.