Ripple is a crypto currency that uses the symbol XRP.
It does not use a blockchain, but instead relies on consensus among a set of servers. It does not use mining. All coins that are going to be in circulation were issued at the launch of Ripple. The coins were held by the "Ripple Company".
It has been said that banks like Ripple more because it is easier to move money around. But many hardcore crypto-currency investors thinks it has many undesirable properties compared to Bitcoin.
The complaint from Bitcoin and other blockchain enthusiasts is that Ripple’s centralized control is the opposite to the ideals and advantages of decentralized blockchains like Bitcoin. To function Ripple also maintains a trusted Unique Node List (UNL) that is meant to guard against potentially malicious or insecure validating servers. It is the UNL that controls the network rules, presenting a conundrum: On the one hand, it protects against problematic validators, but, in theory, a regulating body or government could come in and force a change that isn't necessarily desirable or is downright invasive. Furthermore, because of a FinCEN violation and fine in 2013, Ripple has updated its policies and will only recognize and recommend gateways that are in compliance with financial regulations.