The difference between them is that the real money unlikely will gane a value compared to bitcoin, which has a growing potential every day.
And the obvious money has a physical form and is controlled by the government, and bitkoin, on the other hand, is decentralized and exists in digital form.
Yeah, bitcoin is virtual and there is no physical representation for bitcoin. But, in physical money, there are central banks and money issuers behind it. Despite all, we still trust in bitcoin's unique nature.