Proof of Stake (PoS) is a type of consensus mechanism used by certain blockchains to validate transactions and create new blocks. In PoS, the creator of the next block is chosen via various combinations of random selection and wealth or age (the stake). Unlike Proof of Work (PoW), which requires significant computational power to mine blocks, PoS relies on the staking of cryptocurrency by network participants.
Validators commit a certain amount of their coins as stake and are selected to validate transactions based on the size of their stake and other factors. PoS is considered more energy-efficient than PoW and reduces the risk of centralization that can occur with the accumulation of mining power.