Intermediate
Blockchain
Proof of Stake
A consensus mechanism where validators lock capital and are rewarded or penalised based on honest behaviour.
In simple terms
Instead of burning energy, validators put money at risk. Misbehaving costs them their stake.
Analogy
A security deposit: behave well and you get it back with a reward; cheat and you lose it.
Going deeper
Validators are pseudo-randomly assigned proposal slots and attest in overlapping committees; two conflicting attestations trigger slashing of the deposit. Ethereum's 2022 merge cut network energy use by ~99.95% while keeping the same execution layer.
Common mistake
Assuming Proof of Stake has no cost. The cost is capital at risk, not electricity.