A validator is a participant in a Proof of Stake blockchain network who is responsible for verifying transactions, proposing new blocks, and maintaining the integrity of the blockchain. Validators are the PoS equivalent of miners in Proof of Work systems.
How Validators Work
Validators lock up (stake) a required amount of the network's cryptocurrency as collateral. The protocol selects validators to propose and attest to new blocks. Honest behavior is rewarded with staking yields; dishonest behavior is punished through slashing.
Requirements
Ethereum: Requires 32 ETH to run a validator node, plus dedicated hardware running 24/7.
Solana: No minimum stake, but competitive rewards require significant stake and high-performance hardware.
Delegated Systems: Many networks allow users to delegate their stake to professional validators without running their own infrastructure.
Responsibilities
Block Proposal: Creating new blocks with valid transactions.
Attestation: Voting on the validity of blocks proposed by other validators.
Uptime: Maintaining consistent online presence to avoid penalties.