Digital currency credit cards are actually scams. The so-called digital renminbi is the legal currency issued by the central bank. It has the same value as existing banknotes and a national credit guarantee. For the general public, the functions and properties of digital RMB are exactly the same as banknotes, except that its form is digital and does not need to be bound to any bank account or payment account. It is mainly used to replace M0 currency (cash) circulation, that is, banknotes and coin). Generally speaking, digital RMB and online payment platforms are the difference between "money" and "wallet" - digital RMB combines the advantages of cash and mobile payment, ensuring the convenience of mobile payment while retaining unlimited legal compensation, The anonymity and double offline payment of cash can be circulated on all online payment platforms in the future, and can even break through payment barriers between different platforms and realize mutual transfers. More importantly, digital currencies may play a more important role in the future global financial system. Yi Gang, Governor of the People's Bank of China, said that the research and development and application of legal tender will help effectively meet the public's demand for legal tender under the conditions of the digital economy and improve convenience, security and anti-counterfeiting levels. Retail payment promotes the accelerated development of China’s digital economy.

1. Currency is the product of commodity exchange. It is a commodity that is separated from the commodity world and used as a general equivalent in the process of commodity exchange. It is a currency. Commonly known as money. Currency is a tool for measuring prices, a medium for purchasing goods, and a means of preserving value. It is a contract between the property owner and the market regarding the right of exchange. Essentially, this is an agreement between the owners. Includes currency and banknotes in circulation. There is still much academic debate about the nature of money. The concepts of money in economics are diverse. Initially it was defined based on the function of currency, and later the definition of currency as an economic variable or policy variable was formed. The technical term is currency, which mainly refers to "money in circulation".

2. Economic variables refer to quantities that can change at any time during the operation of the economic system. For example, in the process of analyzing the economic operation of an enterprise, the cost, wages, and profits of the enterprise are all economic variables; when analyzing the trend of regional economic development and operation, regional GDP, GNP, and their growth rates are also economic variables. Variables commonly used in economic analysis and research include endogenous and exogenous variables, stocks and flows. According to Steiner (1981), endogenous variables are “variables that need to be explained within the theory,” whereas exogenous variables are “variables that influence other variables within the theory but are determined by factors outside the theory.” In short, endogenous variables refer to variables determined by factors within the economic system, and exogenous variables refer to variables determined by factors outside the economic system. For example, investment and consumption are endogenous variables when determined by internal factors of the economic system such as national income and interest rates, while population is an exogenous variable when determined by factors external to the economic system such as biology, nature, and society.