The Euro, just like any other government-minted-currency, is defined as a “fiat” currency (that is, has a value because it is imposed by an authority) and has legal tender. A currency has legal tender in a certain territory when no one in that territory can refuse to accept it. On the contrary, Bitcoin does not have legal tender and its acceptance is purely voluntary. Among the main differences is the fact that, while the emission of Euro is regulated by the European Central Bank, the emission of new Bitcoin is predetermined and regulated mathematically, offering more long term guarantees for its users (in terms of purchasing power).