Ripple is a decentralised remittance platform - You can transfer fiat currencies, digital currencies, and commodities.
It uses the blockchain data structure and has its own consensus protocol.
In the Ripple Whitepaper you will not find the term block and blockchain - They use the term ledger instead.
There are two kind of nodes in the system:
Gateway nodes - registered financial institutions, exchanges, merchants, and so on - If you want to become a gateway node in the network you need permission to form a trust chain.
Validators - responsible for validating transactions, anyone can become a validator - but other nodes can keep a list of validators that can actually be trusted.
Regular nodes - Regular people.
The funny part is that there is no consensus to find whom to trust, the user takes the risk of trusting a gateway.
Banks are starting to test and adopt this feature, they are using ripple just as a method to transport their money from Bank A to Bank B with lower fees.
Ripple also has signed contracts with banks to buy the coin at very low prices like 0.005 Cents in any point in time until 2020 due to increased volatility in the market.
Which means that banks are buying directly from a centralised entity so they wont lose any money in this process.
The price of ripple in the market is driven only by regular people and investors trying to gain some profits.
Even though if Ripple gets mass adoption for banks, the price will be manipulated only by regular investors.