What Is Validator?

In PoS networks, validators take the place of miners in Proof of Work. The right to produce blocks is determined not by computing power but by the amount of staked tokens and the protocol's selection rules. For example, running a validator on Ethereum requires staking at least 32 ETH; in each slot, a randomly selected validator proposes a block, while others attest to blocks in committees.

Validators earn income from block rewards and transaction fees. In return, being offline causes small reward losses, while behavior that can harm the network, such as signing two different blocks for the same slot, results in a portion of the stake being cut (slashing). This balance of rewards and penalties provides the network's economic security: someone wanting to attack must put a large amount of tokens at risk.

Running your own validator requires technical knowledge, an uninterrupted internet connection and secure management of keys. For this reason, many users delegate their tokens to a validator or use staking pools and liquid staking protocols; in that case, third-party and smart contract risks arise. The concentration of stake in a few large providers also raises centralization concerns.