Because the currencies of different countries correspond to different convertible goods, or the corresponding standard values are different, the transactions between countries are actually post-transaction standard values, the RMB is the silver standard and the US dollar is the gold standard, so the "values" are different.

National currencies will change because of the changes in total supply and total demand in the economy, so the value of national currencies will fluctuate. For the sake of fair trade between countries, a key word "exchange rate" came into being. Exchange rate changes have a direct regulatory effect on a country's import and export trade.

Under certain conditions, the devaluation of the local currency, that is, lowering the exchange rate, will promote exports and restrict imports; On the other hand, the appreciation of the local currency, that is, the rise of the exchange rate, plays a role in restricting exports and increasing imports.

In this series of regulation and control, there is a gap between currency value and exchange rate, which will lead to differences between each currency and the goods behind it.

Strictly speaking, there is no difference between valuable currency and worthless currency, but the standard value stipulated by banks is different. RMB is the silver standard, and the exchange rate is generated by the leverage in the silver standard.