Ripple positions itself as a complement to, rather than a competitor with, Bitcoin - the site has a page dedicated to Ripple for bitcoiners. Ripple is a distributed network which means transactions occur immediately across the network - and as it is peer to peer - the network is resilient to systemic risk. Ripples aren't mined - unlike bitcoin and its peers - but each transaction destroys a small amount of XRP which adds a deflationary measure into the system. There are 100 billion XRP at present.
The Ledger and Consensus
The Ripple protocol is, at its core, a shared public database. This database includes a ledger, which serves to track accounts and the balances associated with them. The ledger is a distributed database — a perfect, shared record of accounts, balances, and transactions in the Ripple protocol. It is continually and automatically updated by the Ripple Transaction Protocol (RTXP) so that an identical ledger exists on thousands of servers around the world. At any time, anybody can review the ledger and see a record of all activity on the Ripple protocol. When changes are made to the ledger, computers connected to the Ripple protocol will mutually agree to the changes via a process called consensus. The Ripple protocol reaches consensus globally within seconds of a change being made. The consensus finding process is the engineering breakthrough that allows for fast, secure, and decentralized transaction settlement on the Ripple protocol.
The World’s First Distributed Exchange
No one owns or controls the Ripple protocol. It runs on computers around the world, all working together to continually maintain a perfect, shared record of accounts, balances, and transactions. Distributed networks offer many efficiencies over centralized networks. Because the network is “self-clearing”, it eliminates the need for a centralized network operator (and gets rid of the associated layer of fees). Because there is no single point of failure, distributed networks are more reliable. They also tend to be more secure, due to their open source nature.
Ripple (XRP) uses the N/A algorithm and relies on the N/A proof type.