Standard crypto-coins are a code-based resource built to work as a medium of exchange. New coins are created by mining. Anyone can do this if they've access to a computer. Mining uses a great deal of time and electrical power, though. A high-powered computer is also required, to mine effectively. Conversely, Ripple is a centralised asset, which cannot be mined. A fixed number of units were created by the company and this limit will never be added to.