What is Fast Byzantine Fault Tolerance (FBFT)?

Fast Byzantine Fault Tolerance (FBFT) is a consensus mechanism used on some Proof-of-Stake (PoS) blockchains. A variation of Practical Byzantine Fault Tolerance (pBFT), FBFT has the block leader collect votes from validators using a multi-signature signing process in lieu of asking all validators to broadcast their vote (as done on pBFT chains). This allows FBFT to be "faster" and more scalable than pBFT consensus-based chains. While pBFT works well with distributed networks, many consider FBFT more robust for decentralized networks like blockchains as it allows nodes to sync using a local clock and the last block's timestamp.