Why flat money has value?

Fiat money has value primarily because a government maintains it and people have faith in its ability to serve as a medium of exchange. Unlike commodity money, which is backed by physical assets (like gold), fiat money derives its value from the trust and confidence of the public in the stability of the issuing government and its economy. Additionally, fiat money is widely accepted for transactions and can be used to settle debts, reinforcing its value in everyday commerce.