Currency is any item or verifiable record that is generally accepted for the payment of goods and services and the repayment of debts in a particular country or socio-economic context, or that is easily converted to this form. The main functions of [need to quote] currency are different from: exchange medium; accounting unit; value storage; sometimes the standard of deferred payment. Any project or verifiable record that satisfies these functions can be considered money.

Historically, money is an emerging market phenomenon of establishing commodity money, but almost all contemporary monetary systems are based on legal tender. Legal tender, like any check or debt instrument, has no use value as tangible goods. It is declared by the government as legal tender and generates its value; that is, it must accept payment of "all public and private debts" in the country.

The money supply of a country includes money (notes and coins) and, depending on the specific definition used, one or more types of bank money (balances in checking accounts, savings accounts and other types of bank accounts). Bank money is only composed of records (most of which are computerized in modern banking industry), and it is the largest part of broad money in developed countries.