Centralised crypto is a code-based resource designed to be used as a medium of trade. Additional coins may be added through mining. Everyone can get involved if they have a a computer. Mining uses a great deal of time and electrical energy, however. A fast computer is also vital, to do this profitably. On the other hand, Ripple is a centralised coin, which can't be mined. A finite number of coins were created by the organisation and this number will never be exceeded.