Centralised crypto is a digital resource built to be employed as an apparatus of trade. New units may be added by mining. Any person is able to do this if they have a a computer. Mining requires a lot of time and electrical power, however. A high-powered machine is also needed, to do this effectively. Conversely, Ripple is a centralised resource, which cannot be mined. A limited number of coins were generated by the company and this number will not be exceeded.