Stellar is an open-source, distributed payments infrastructure. It is a leapfrog technology that connects people, payment systems, and banks with a focus on the developing world. It lets you facilitate multi-currency and asset transactions quickly, reliably, and for a fraction of a penny by using a crypto-asset called Lumens (XLM) as a bridge.
Stellar's basic operation is similar to that of most decentralized payment technologies. It runs a network of decentralized servers with a distributed ledger that is updated every 2 to 5 seconds among all nodes. The most prominent distinguishing factor between Stellar and bitcoin is its consensus protocol.
Stellar’s consensus protocol does not rely on the entire miner network to approve transactions. Instead, it uses the Federated Byzantine Agreement (FBA) algorithm, which enables faster processing of transactions. This is because it uses quorum slices (or a portion of the network) to approve and validate a transaction.
Each node in the Stellar network chooses another set of “trustworthy” nodes. Once a transaction is approved by all nodes within this set, then it is considered approved. The shortened process has made Stellar's network extremely fast and it is said to process as many as 1,000 network operations per second.