Centralised crypto is a code-based holding built to work as a medium of trade. crypto-coins can be added by mining. Any person can do this if they have a a device. Mining uses a large amount of hours and electrical energy, though. A high-powered machine is also needed, to do this effectively. On the other hand, Ripple is a centralised asset, which cannot be mined. A fixed amount of coins were generated by the company and this limit will never be exceeded.