Byzantine Generals’ Problem

The Byzantine Generals' Problem is a well-known abstraction that revolves around the context of distributed computer systems (of which Blockchain is a prime example).

Cryptocurrencies are essentially distributed computer systems: networks made up of various nodes run by independent persons or organizations that compete to process transactions and add them to the Blockchain's conclusion.

With nodes geographically distant and independent of each other or any central authority, it is hard to determine which nodes are producing erroneous transaction information – whether purposefully or by mistake.

Byzantine Fault Tolerance is a quality of a distributed computer system that allows it to overcome this challenge and continually build agreement even if some nodes disagree with the rest, either mistakenly or by design.