Proof of Stake
Consensus mechanism where validators stake crypto instead of burning electricity.
Proof of Stake (PoS) is a consensus algorithm in blockchain networks where validators must lock (stake) a certain amount of cryptocurrency as collateral to participate in validating transactions and creating new blocks.
Unlike Proof of Work (Bitcoin), PoS doesn't require massive computing power — validators are selected based on stake size. It's much more energy efficient.
Ethereum switched from PoW to PoS in 2022 (The Merge), reducing energy consumption by ~99.95%. Other PoS chains: Solana, Cardano, Polkadot, Avalanche.
Downside: "the rich get richer" — whoever has more tokens earns more.