Several users has described the major difference that's the virtual usage. It cannot be used same as our fiat currency. It requires some basic understanding for using it as everything is linked to technology and internet. Real money is simple that even an uneducated man can use without difficulty.
I agree, some people will even say bitcoin is illegal because it comes from the deepweb. But for those people that are technology literate, they will always know bitcoin and how it works. People around me don't know anything at all about bitcoin, they just know i earn online and the money i earn were always sent to my bank account.
Not just illegal some countries have ban it for good and who used it will be punished by law, and they are cases where some countries are want to develop there own crypto coin which is very good. Still differences are and it will be for both fiat and crypto in future.