 Commodity money is to be distinguished from representative money, which is a certificate or token which can be exchanged for the underlying commodity, but only by a formal process.A key feature of commodity money is that the value is directly perceived by its users, who recognize the utility or beauty of the tokens as goods in themselves.Since payment by commodity generally provides a useful good, commodity money is similar to barter, but is distinguishable from it in having a single recognized unit of exchange.