As for the interest rate in China, it usually refers to the "benchmark interest rate for RMB deposits and loans of financial institutions". This interest rate is to be observed by financial institutions all over the country, in other words, it is consistent throughout the country. During the same period, the deposit and loan interest rates of any bank are the same.
As for their functions, supply and demand and interest rates have always influenced each other. In practice, alan greenspan, the former chairman of the Federal Reserve, successfully set interest rates for many years to maintain the long-term expansion of the American economy, which can also be said to be the interest rate control of supply and demand. On the other hand, market supply and demand naturally affect the formulation of interest rates. Therefore, I think it is wrong to say that the former controls the latter or vice versa. In the final analysis, the relationship between supply and demand is determined by the overall economic situation, the specific development of all walks of life, and the perfection of the credit system. Of course, interest rates have a passive constraint on the consideration of bank financing and borrowing costs, as well as the financing costs of enterprises or individuals, and also have a considerable impact on "supply and demand".
However, interest rates also have the characteristics of marketization. In areas with mature market economy and developed financial and banking systems, interest rates often reflect the reality of market supply and demand. On the contrary, under the immature and unstable conditions of China's current financial and banking system, the supply and demand situation reflected by interest rates is greatly deviated.
By the way, by definition, the federal funds rate in the United States is more like LIBOR, the so-called London Interbank Offered Rate. SIBOR (Singapore) and Hong Kong Interbank Offered Rate (Hong Kong) can be obtained by analogy. In China, the same property is called SHIBOR.