What is money?
Money is commonly defined according to its functional roles. These are money as a measure of value (also referred to as a unit of account), a medium of exchange, a store of value, and a standard of deferred payments.
Modern money consists primarily of two types of monetary instruments. The first is the notes and coins issued by central banks (fiat money). This is most commonly understood by the proverbial man on the Clapham omnibus to be money.