Money is a tool, used as a medium of transaction, a store of value and a unit of account. It is a special commodity that acts as an equivalent in the exchange of goods and services, and it is a material appendage and symbol appendage of people's commodity value. It includes not only currency in circulation, especially legal tender, but also various savings deposits. In the modern economic field, only a small part of the currency field is displayed in the form of physical currency, that is, practical paper money or coins, and most transactions use checks or electronic money.

Wealth is something valuable to people-money, wealth and property, especially their accumulation, retention and use, and it is a prominent symbol of the middle class-national wealth.

Market liquidity is a business term, which refers to the ability to buy and sell an item quickly in the market without causing large price fluctuations. Usually refers to liquidity.

Foreign exchange is the creditor's rights held by the monetary management authorities (central bank, monetary management 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. , which can be used when the balance of payments is in deficit.

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.). ).