A validator is a participant in a blockchain network who validates and verifies transactions and blocks using a consensus algorithm, often Proof of Stake (PoS) or Delegated Proof of Stake (DPoS).
By verifying the legality of transactions and adding them to the blockchain, validators safeguard the correctness and security of the ledger. In PoS systems, validators are selected to produce new blocks and are motivated to abide by the network’s rules to preserve its integrity.