some people may not accept cattle as money. In contrast, people are more than willing to accept 20-dollar bills. In fact, the U.S. government protects your right to use U.S. currency to pay your bills. Well, it seems "udderly" clear at this point thatbased on the characteristics of moneyU.S. 20-dollar bills are a much better form of money than cattle. To summarize, money has taken many forms through the ages, but money consistently has three functions: store of value, unit of account, and medium of exchange. Modern economies use fiat money-money that is neither a commodity nor represented or "backed" by a commodity. Even forms of money that share these function may be more or less useful based on the characteristics of money