What Is the Primary Difference between Proof-of-Work and Proof-of-Stake Consensus Mechanisms?

Proof-of-Work (PoW) relies on computational power (mining) to solve complex puzzles and validate transactions. This is energy-intensive but historically secure.

Proof-of-Stake (PoS) relies on validators staking capital (cryptocurrency) to be selected to propose and attest to new blocks. PoS is significantly more energy efficient and offers different economic security guarantees.

The core difference is energy-based competition versus capital-based security.