Ethereum uses proof of stake to coordinate agreement on blocks. Validators deposit ETH, run execution and consensus software, and participate in block proposals and attestations.
Proposals and attestations
One validator is selected to propose a block in a slot, while committees of validators attest to blocks. Other nodes re-execute transactions and verify the resulting state.
A validator depends on several software roles
Ethereum validators use an execution client, consensus client, and validator client. Correct operation, connectivity, and key protection all affect participation.
Rewards, penalties, and slashing
Validators can earn rewards for correct participation and lose ETH for inactivity or provably conflicting behavior. Staking is therefore an operational responsibility, not a guaranteed yield.
Staked ETH is exposed to protocol penalties
Rewards are conditional on correct participation. Extended downtime or slashable behavior can reduce the validator’s balance.
Sources
Educational information, not investment advice.