Fiat money differs from representative currencies because it is not based on the value of a commodity and is not redeemable for any underlying asset such as gold or precious metals. Instead, a fiat currency is backed by the issuing government and relies on trust and faith in that government to maintain its value. The advantage of fiat currency is that governments collect taxes on the same money. Hence, a denomination maintains a perceived value in almost any circumstance because tax obligations are an ingrained aspect of modern society. Another concept is the credit theory, which suggests that all money in any currency is a relationship between credit and debt, so it does not necessarily need a physical commodity to imply a value.