Byzantine Fault Tolerance (BFT) blockchains protect the network from faulty or malicious nodes by ensuring consensus even when some participants act dishonestly. This model is based on the Byzantine Generals Problem, where nodes agree on a common decision despite failures or attacks. Protocols like Tendermint, HotStuff, and PBFT use BFT to power secure and reliable blockchains. BFT consensus offers strong security and fast finality, making it ideal for financial applications, enterprise-grade systems, and decentralized networks where trust and performance are critical.