What is proof of stake? How validators replaced miners

Every twelve seconds, the Ethereum network asks a question that would have seemed absurd before 2022: who gets to write the next page of a $400 billion ledger, and how do you stop them from lying? The answer, for Ethereum and the majority of active blockchains by market value, is proof of stake, a consensus mechanism that replaced the energy-intensive puzzle-solving of proof of work with a simpler, older idea: put your money where your mouth is. Validators lock cryptocurrency as collateral, propose and verify blocks, and face the destruction of their deposit if they cheat. No mining rigs, no electricity arms race, no warehouse full of ASICs. Just capital at risk and code that enforces the consequences. Summary Proof of stake secures blockchains by requiring validators to lock cryptocurrency as collateral, replacing the computational competition of proof of work with economic incentives and penalties. Ethereum’s September 2022 Merge was the largest proof-of-stake transition in history, cutting the network’s energy use by 99.95% while enabling a path to future scaling upgrades. The mechanism now underpins the majority of major blockchains by market cap, but carries its own risks: cen...