What is Practical Byzantine Fault Tolerance (pBFT)?

Practical Byzantine Fault Tolerance (pBFT) is a consensus mechanism designed to improve upon the Byzantine Fault Tolerant (BFT) consensus mechanism in order to more fully protect against Byzantine faults which occur in distributed networks. Originally created in the early 1990s by Barbara Liskov and Miguel Castro, pBFT is used to maintain consensus on a wide variety of distributed computer systems and blockchain platforms. Designed to work in asynchronous systems and optimized for low overhead, pBFT was designed to solve many of the problems associated with typical Byzantine Fault Tolerant consensus methods.