Currency that you can quickly convert into another type of currency is convertible money. Currency that you cannot convert into another type of currency is inconvertible money.Certificates that you can exchange for a specific quantity of a commodity or a certificate that represents money but is not actually money is representative money.iat money is typically the paper money of a country, such as the U.S. dollar or Japanese yen. A commodity such as gold or silver does not back the value of fiat money, which is subject to devaluation due to economic crises such as hyperinflation.