Consensus Algorithm

A consensus algorithm answers the hardest question in crypto: with no boss, who decides which transactions are real and in what order? It's the set of rules that lets strangers who don't trust each other agree on one version of the ledger.

The two big families are proof of work, where miners spend computing power for the right to add a block, and proof of stake, where validators put up coins as a deposit. Variants like proof of staked authority trade some decentralization for speed. All of them make cheating more expensive than playing fair.