CBDC, or Central Bank Digital Currencies, are digital forms of money issued and controlled by central banks, offering a centeralized alternative to decentralized cryptocurrencies. Fiat money, on the other hand, refers to government-issued currency that is not backed by a commodity such as gold, and its value is derived from government decree and credit. The key difference lies in their form and issuance: CBDC is digital and issued by central banks, while fiat money can be in physical or electronic form and is controlled by governments.