In order for Bitcoin to exist, fiat currency must first exist. Fiat currency is government-issued currency that is not backed by a physical commodity.
The value of fiat currency is based on the faith and credit of the issuing government. Without fiat currency, there would be no way to value Bitcoin.
Bitcoin is a decentralized digital currency, which means it is not subject to government control or manipulation. The value of Bitcoin is based on market demand and supply.
There is a limited supply of 21 million Bitcoin, which gives it a scarcity value. Bitcoin also has utility value, as it can be used to purchase goods and services online.
Due to its decentralized nature, Bitcoin can exist without fiat currency. However, without fiat currency, Bitcoin would not have any value.
Fiat currency is necessary to value Bitcoin, but Bitcoin does not require fiat currency to exist.