Proof of Stake (PoS) is the consensus mechanism used by Ethereum (since The Merge in 2022), Cardano, Solana, Avalanche, and most modern blockchains. Instead of expending computational energy to mine blocks, PoS requires validators to lock up (stake) cryptocurrency as collateral to earn the right to validate transactions. Validators are selected proportionally to their stake – the more tokens staked, the greater the chance of being chosen. If a validator misbehaves, their staked tokens are slashed (partially destroyed) – an economic penalty making attacks financially irrational. PoS is dramatically more energy-efficient than Proof of Work: Ethereum moved to PoS reduced energy consumption by ~99.95%. Variants include Delegated PoS (DPoS), Nominated PoS (NPoS), and Pure PoS. Most modern Layer 1 blockchains use PoS or a variant. The minimum stake to run an Ethereum validator is 32 ETH; protocols like Lido and Rocket Pool lower this threshold through liquid staking pools, issuing tradeable receipt tokens (stETH, rETH) for staked positions.
Example: Example: A solo staker locks 32 ETH, runs validator software 24/7, and earns ~4% APR in ETH rewards. If they go offline excessively or attempt to double-sign blocks, they face slashing – losing a portion of their stake. Economic collateral keeps validators honest without requiring massive energy expenditure.
Learn more: Ethereum.org – Proof of Stake
