Validator
A participant in a proof-of-stake network that proposes and approves blocks, backed by a deposit that can be cut for misbehavior.
A validator runs full node software plus signing keys and a deposit, and its duties are mechanical: attest to the head of the chain on schedule and produce a block when selected. Ethereum fixes the deposit per validator identity at 32 ether, so large operators run many identities and pooled or liquid staking services let smaller holders delegate to operators who run the machines. Rewards accrue for timely correct attestations, ordinary downtime causes small inactivity penalties, and only provably contradictory signatures trigger slashing. The distinction from a plain full node is the stake and the signing keys; the validator's discretion extends to which transactions it includes and in what order, not to what counts as valid.
En pratique
A validator that is offline for a few hours loses a small amount through inactivity penalties, while one that signs two different blocks for the same slot is slashed and ejected.
Le malentendu courant
A validator does not decide which transactions are valid; validity is fixed by the protocol rules, and every other node rejects a block that breaks them.
Le chiffre auquel cela correspond
The number of validators currently participating in a proof-of-stake network's consensus.
Limites: A validator is not an operator and not a person. Ethereum caps the effective stake per validator key, so a single professional operator can run thousands of validators and the count grows with stake rather than with the number of independent participants. Chains with a fixed active set report a…