What is the difference between fiat currency and Cryptocurrency?

Fiat currency is currency that a government has declared to be legal tender. It is backed by the government that issued it, and its value is based on supply and demand. Cryptocurrency is a digital asset designed to work as a medium of exchange that uses cryptography to secure its transactions, to control the creation of additional units, and to verify the transfer of assets. Unlike fiat currency, it is not backed by any central bank or government. Cryptocurrency has a decentralized nature, meaning that it is not subject to government control, and is instead managed by the users on the ledger.