From the coins of yesteryear, whose exchange value was deemed to be tangible (since it was inherent to the precious metals from which they were made), to paper money (coins and notes), the evolution of currency has always gone hand in hand with the practices of economic actors and technological change. It has always been an essential instrument of economic activity and a tool of state sovereignty.
With no “material” existence, book money circulates between economic actors thanks to different methods of payment (for example. debit and credit cards, wire transfers, cheques) and is transferred from one commercial bank to another through a book transaction. It represents around 90% of the money stock in circulation, way ahead of the paper money issued by central banks.