1 ETH in USD = $0.0000000
Fiat Currency is basically good old paper money or in fancier terms: "a government-issued currency that is not backed by a commodity such as gold". (Investopedia)
Crypto Currency is basically "impossible-to-fake" electronic money or in fancier terms: "a digital or virtual currency that is secured by cryptography, which makes it nearly impossible to counterfeit or double-spend". (Investopedia)