What Is the Difference between a “Validator” and a “Miner” in Blockchain Consensus?

A "miner" operates in a Proof-of-Work system, expending computational power (hash rate) to solve a cryptographic puzzle and create a new block. They are rewarded with the block subsidy and transaction fees.

A "validator" operates in a Proof-of-Stake system, putting up financial collateral (stake) to be randomly selected to propose and attest to new blocks. They are rewarded with transaction fees and newly minted tokens.

The key difference is the cost of participation: energy for miners, capital for validators.