Validator

A validator is a participant in a proof-of-stake network chosen to propose and confirm blocks, typically after locking up (staking) a required amount of the networks coin as collateral. Validators are rewarded for honest participation and can lose part of their stake for misbehaviour or downtime, an approach that secures the chain economically rather than through heavy computation.

A common misconception is that validators just “mine” more efficiently; they are selected by stake and protocol rules, not raw hashing power. See what miners and validators do.