There are many differences of bitcoin and real money.. bitcoin you can use it online as alternative real money you can buy anytime there.. in bitcoins you should have too because many other will exchange it fast and instanly in our place.
Base on my researching that said the money in any form when in actual use or circulation as a medium of exchange, especially circulating banknotes and coins. And the bitcoin is there is no central authority creating new money or clearing transactions.