Standard cryptocurrency is a code-based resource designed to work as a medium of trade. New units can be created via mining. Any person may do this if they have a a computer. Mining uses a large amount of time and electricity, though. A high-powered machine is also needed, to do this effectively. Conversely, Ripple is a centralised coin, which is unmineable. A fixed supply of units were made by the organisation and this number will never be added to.