Medium of exchange in the context of "Currency"

Money is any item or verifiable record that is generally accepted as payment for goods and services and repayment of debts, such as taxes, in a particular country or socio-economic context. The primary functions which distinguish money are: medium of exchange, a unit of account, a store of value and sometimes, a standard of deferred payment.

Money was historically an emergent market phenomenon that possessed intrinsic value as a commodity; nearly all contemporary money systems are based on unbacked fiat money without use value. Its value is consequently derived by social convention, having been declared by a government or regulatory entity to be legal tender; that is, it must be accepted as a form of payment within the boundaries of the country, for "all debts, public and private", in the case of the United States dollar.

In economics, standard of deferred payment is a function of money. It is the function of being a widely accepted way to value a debt, thereby allowing goods and services to be acquired now and paid for in the future.

The 19th-century economist William Stanley Jevons, influential in the study of money, considered it to be one of four fundamental functions of money, the other three being medium of exchange, store of value, and unit of account. However, most modern textbooks now list only the other three functions, considering standard of deferred payment to be subsumed by the others.

Commodity money is money whose value comes from a commodity of which it is made. Commodity money consists of objects having value or use in themselves (intrinsic value) as well as their value in buying goods.This is in contrast to representative money, which has no intrinsic value but represents something of value such as gold or silver, for which it can be exchanged, and fiat money, which derives its value from having been established as money by government regulation.

Examples of commodities that have been used as media of exchange include precious metals and stones, grain, animal parts (such as beaver pelts), tobacco, fuel, and others. Sometimes several types of commodity money were used together, with fixed relative values, in various commodity valuation or price system economies.

Fiat money is a type of government-issued currency, authorized by government regulation to be legal tender. Typically, fiat currency is not backed by a precious metal, such as gold or silver, nor by any other tangible asset or commodity. Since the end of the Bretton Woods system in 1976 by the Jamaica Accords, all the major currencies in the world are fiat money.

Fiat money generally does not have intrinsic value and does not have use value. It has value only because the individuals who use it (as a unit of account or, in the case of currency, a medium of exchange) agree on its value. They trust that it will be accepted by merchants and other people as a means of payment for liabilities.

A currency is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes, coins, electronic balances in bank accounts, and central bank digital currencies (CBDCs). A more general definition is that a currency is a system of money in common use within a specific environment over time, especially for people in a nation state.

In trade, barter (derived from bareter) is a system of exchange in which participants in a transaction directly exchange goods or services for other goods or services without using a medium of exchange, such as money. Barter is considered one of the earliest systems of economic exchange, used before the invention of money. Economists usually distinguish barter from gift economies in many ways; barter, for example, features immediate reciprocal exchange, not one delayed in time. Barter usually takes place on a bilateral basis, but may be multilateral (if it is mediated through a trade exchange). In most developed countries, barter usually exists parallel to monetary systems only to a very limited extent. Market actors use barter as a replacement for money as the method of exchange in times of monetary crisis, such as when currency becomes unstable (such as hyperinflation or a deflationary spiral) or simply unavailable for conducting commerce.

No ethnographic studies have shown that any present or past society has used barter without any other medium of exchange or measurement, and anthropologists have found no evidence that money emerged from barter. Nevertheless, economists since the times of Adam Smith (1723–1790) often imagined pre-modern societies for the sake of showing how the inefficiency of barter explains the emergence of money and the economy, and hence the discipline of economics itself.