CurrencyA currency is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins. 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. Under this definition, the British Pound Sterling (£), euros (€), Japanese yen (¥), and U.S. dollars (US$) are examples of (government-issued) fiat currencies.
Gold standardA gold standard is a monetary system in which the standard economic unit of account is based on a fixed quantity of gold. The gold standard was the basis for the international monetary system from the 1870s to the early 1920s, and from the late 1920s to 1932 as well as from 1944 until 1971 when the United States unilaterally terminated convertibility of the US dollar to gold, effectively ending the Bretton Woods system. Many states nonetheless hold substantial gold reserves.
HyperinflationIn economics, hyperinflation is a very high and typically accelerating inflation. It quickly erodes the real value of the local currency, as the prices of all goods increase. This causes people to minimize their holdings in that currency as they usually switch to more stable foreign currencies. When measured in stable foreign currencies, prices typically remain stable. Unlike low inflation, where the process of rising prices is protracted and not generally noticeable except by studying past market prices, hyperinflation sees a rapid and continuing increase in nominal prices, the nominal cost of goods, and in the supply of currency.