Byzantine General Problem is an example of the difficulty in building consensus among the nine units of the Byzantine Empire to attack a country.
The nine units had to decide whether to go on the offensive against the target country or to withdraw.
Four units communicated their intention to withdraw, and four communicated their intention to attack.
The general, who judged that his decision would determine the majority, deliberately communicated his intention to retreat to the troops who expressed their intention to retreat, and his intention to attack to the troops who expressed their intention to attack.
This resulted in a disjointed response, with four units withdrawing and four going on the offensive, and they were defeated by the enemy.
Bitcoin’s Byzantine General Problem
The Bitcoin transaction system has a decentralized network structure with no central management system.
Each computer can interact with other computers, but there is no main computer that controls the whole. The question is whether the whole system can form the right consensus.
Bitcoin overcame this Byzantine problem by adopting a blockchain structure (where the longest blockchain is the correct one) without an administrator.