"Money supply M0 refers to the total amount of all circulating cash and bank deposit reserves issued by a country or region at a specific point in time. It is the currency base of a country or region and the most basic of money supply one of the indicators.

Specifically, M0 includes all coins and banknotes in circulation, as well as reserves held by banks at the central bank. These forms of money are the most immediate and basic forms and the basis for the rest of the money supply.

Money supply M0 plays an important role in macroeconomics because it affects the monetary policy and inflation of a country or region. When M0 increases, it may lead to higher inflation, and when M0 decreases, it may lead to deflation and lower prices.

Money supply M0 is an important macroeconomic indicator, which plays an important role in the government's formulation of monetary policy, control of inflation and maintenance of economic stability. "