Gold coins - Gold coins were once in wide circulation until fiat money took their place. Fiat money is simply the paper bills that you now carry in your wallet. Paper money in the U.S. is now a Federal Reserve NOTE that is actually a note that promises an exchange value yet carries no real value other than what is assigned to it. It was preceded by a silver or gold certificate that represented the actual value of the certificate in that gold and silver really backed the certificate in the denominations shown.