Centralised cryptocurrency is a digital resource created to be used as an apparatus of trade. New units can be created by mining. Anyone may do this if they have a a device. Mining uses a large amount of time and electrical energy, though. A fast computer is also vital, to do this effectively. Conversely, Ripple is a centralised coin, which is unmineable. A limited amount of coins were created by the company and this amount will not be added to.