But WTF is that anyway?
The Byzantine Generals Problem is an age-old game theory problem, where several generals are besieging Byzantium.
If all generals attack at the same time they win, but if they attack at different times or one faulty general chooses not to fight, they lose.
The generals have no secure communication channel, as any message they send or receive may have been intercepted or deceptively sent by Byzantium’s defenders.
Interesting, Isn't it?
This same problem followed in the computing world, where decentralized parties face difficulty in arriving at a consensus without relying on a trusted central party.
So how it can be solved?
Bitcoin managed to solve the Byzantine Generals Problem by using a "proof-of-work"
To add information, a member of the network must publish proof that they invested considerable work into creating the block of information.
If any member of the network attempts to broadcast false information, all nodes on the network will immediately recognize it as objectively invalid and ignore it.
The false broadcaster will have wasted the work that was required for their attempt to spread the false message.
This makes it too expensive for any "Byzantine general" (bitcoin node) to lie.
Because each node can verify all information independently, it makes Bitcoin a trustless system.
That's how Bitcoin    solved the Byzantine Generals problem.
What Satoshi did was a one-time discovery and cannot be reinvented.