In macroeconomics, money supply refers to the total volume of money held by the public at a particular point in time. There are several ways to define "money", but standard measures usually include currency in circulation and demand deposits. Money supply data is recorded and published, usually by the national statistical agency or the central bank of the country. Empirical money supply measures are usually named M1, M2, M3, etc., according to how wide a definition of money they embrace. The precise definitions vary from country to country, in part depending on national financial institutional traditions.

A banknote—also called a bill, paper money, or simply a note—is a type of negotiable promissory note, made by a bank or other licensed authority, payable to the bearer on demand. Banknotes were originally issued by commercial banks, which were legally required to redeem the notes for legal tender when presented to the chief cashier of the originating bank. These commercial banknotes only traded at face value in the market served by the issuing bank. Commercial banknotes have primarily been replaced by national banknotes issued by central banks or monetary authorities.