Centralised crypto is a code-based resource built to work as a medium of exchange. Additional coins may be added through mining. Anyone can get involved by using their a device. Mining uses a great deal of time and electricity, however. A powerful machine is also required, to mine successfully. Conversely, Ripple is a centralised resource, which can't be mined. A limited amount of coins were made by the company and this number will not be added to.