consensus-mechanisms

A <a href="/en/glossary/consensus-mechanisms/51-percent-attack/">51% Attack</a> occurs when a single entity gains control of more than half of a blockchain's <a href="https://crypto-bible.com/en/glossary/blockchain-fundamentals/block/" target="_blank" rel="noopener">Block</a>-production power (hash power on PoW chains, staked tokens on PoS chains), letting them rewrite recent transaction history and double-spend their own funds — but not steal assets from other people's wallets.

A <a href="/en/glossary/consensus-mechanisms/consensus-mechanism/">Consensus Mechanism</a> is the set of rules that lets mutually distrusting nodes scattered around the world agree on what the next entry in a shared ledger should be — the core reason a blockchain can function without a central authority.