일론 머스크, "암호화폐는 현금 대체 수단"
Economists define cash as a physical form of money, such as banknotes and coins. Bookkeepers and financiers explain cash money as a current asset, including currency or its equivalent, that can be accessed immediately. Cash existed in the form of coins until Venetian merchants started using the first banknotes in the early Middle Ages. Today, most cash is being replaced by digital money, which has become the largest share of the total money supply. While cash is not useful for remote payments and is not as fast as digital currency, it is very convenient for private and secure transactions — though this is gradually being replaced with cryptocurrencies. In 2016, 1 out of 7 people in the UK were reportedly no longer using cash, which may indicate the possible existence of a cashless society in the near future — proposals of which are coming from around the world.