What is difference between fiat money an commodity money?

Fiat money is currency that has no intrinsic value and is not backed by any physical commodity; its value is derived from government regulation and public trust. In contrast, commodity money is based on a physical good, such as gold or silver, which has inherent value. While fiat money is widely used in modern economies, commodity money was more common in earlier times, reflecting tangible assets. Essentially, fiat relies on faith in the issuing authority, whereas commodity money has value based on the actual commodity.