Proof of Stake (commonly abbreviated as PoS) is a type of consensus mechanism used by some cryptocurrencies. In a PoS system, the creator of the next [[block]] on the [[blockchain]] is chosen depending on their stake in the cryptocurrency.
In contrast to [[proof of work]] systems, which use computational power to validate transactions and produce new blocks, PoS systems use a combination of random selection and stake (or ownership) to determine who will create the next block. This usually makes the process of validating transactions and producing new blocks more energy-efficient, as it does not require as much computational power.
In September 2022, the Ethereum blockchain made a historic switch from proof of work to proof of stake, when the mainnet merged with the Beacon chain. Newer cryptocurrencies, such as Tezos and Cardano, also use proof of stake.