What is the difference between proof of work and proof of stake in cryptocurrency?

Proof of Work (PoW) and Proof of Stake (PoS) are two consensus mechanisms used by blockchain networks to validate transactions and secure the network. In PoW, miners compete to solve complex cryptographic puzzles, with the first to solve the puzzle earning the right to add a new block to the blockchain. This process consumes significant energy and computational power. In contrast, PoS relies on validators who lock up (or “stake”) a certain amount of cryptocurrency as collateral to validate transactions. Validators are chosen based on the amount of cryptocurrency they have staked, and they are rewarded with transaction fees or new coins. PoS is considered more energy-efficient than PoW.