Consensus
Also known as: Distributed Agreement, Network Consensus, Blockchain Finality Mechanism
The process by which nodes in a blockchain network agree on the validity of transactions and the state of the ledger.
Consensus is a foundational concept in blockchain that ensures all participants in a decentralized network agree on a single version of truth. It allows for trustless cooperation without a central authority. Consensus mechanisms like Proof of Work, Proof of Stake, and their variants (e.g., PBFT, HotStuff, Tendermint) define how nodes propose, validate, and finalize blocks. Effective consensus ensures network security, prevents double-spending, and enables decentralization. Choosing the right consensus model impacts performance, energy use, and fault tolerance.