Money is historically an聽emergent market phenomenon聽establishing a聽commodity money, but nearly all contemporary money systems are based on聽fiat money.[聽Fiat money, like any check or note of debt, is without聽use value聽as a physical聽commodity.
It derives its value by being declared by a聽government聽to be聽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”.[Counterfeit money聽can cause聽good money聽to lose its value.
The use of barter-like methods may date back to at least 100,000 years ago, though there is no evidence of a society or economy that relied primarily on barter. Instead, non-monetary societies operated largely along the principles of gift economy and debt. When barter did in fact occur, it was usually between either complete strangers or potential enemies.
Informaci贸n tomada de https://en.wikipedia.org/wiki/Money