What type of money is used by the United States?

The type of money used by the United States is fiat money, which is currency that a government has declared to be legal tender but is not backed by a physical commodity like gold or silver. Instead, its value is derived from the trust and confidence that people have in the government that issues it. This system allows for greater flexibility in monetary policy, as the government can increase or decrease the money supply as needed to influence economic activity.

Fiat money is widely accepted for transactions and is used to pay debts. In the case of the U.S. dollar, it is recognized both domestically and internationally, which facilitates trade and economic stability.

Commodity money, which is backed by a physical substance, and hard currency, which typically refers to a stable and widely accepted currency, differ from fiat money in their foundational value. Barter money involves trading goods and services directly without a standard form of currency, which is not the case in a modern economy such as that of the United States.