What is the difference between commodity money and fiat money? Why do people accept fiat money in trade for goods and services?

Commodity money has "intrinsic value," or value in uses other than as money. Fiat money is established as money by the government. It has very little, if any, intrinsic value. Although fiat money has no intrinsic value, people accept it in trade when they are confident that others will also accept it. The government's decree that fiat currency serves as legal tender increases this confidence.