Foreign exchange refers to all assets owned by a country in foreign currency. It refers to the flow of money between countries and a specialized commercial activity of exchanging one country's currency for another country's currency to pay off international creditor's rights and debts. Including foreign currency, foreign currency deposits, foreign currency securities (treasury bonds, treasury bonds, corporate bonds, stocks, etc.). ) and foreign currency payment vouchers (bills, bank deposit vouchers, postal savings vouchers, etc.). ).

Foreign currency refers to the currency other than "bookkeeping base currency", which is the bookkeeping base currency relative to the domestic currency, and is specifically manifested as the currency other than "bookkeeping base currency" in accounting.