Proof-of-Stake (PoS)

Proof-of-stake is a consensus mechanism.  Cryptocurrency relies on a consensus mechanism (how blockchains function and are trusted by their users). 

With the proof-of-stake mechanism, validators (the block creators) must own (stake) coins to participate. When a block is successfully confirmed, validators receive fees as rewards. 

Ethereum, Cardano, Solana and Avalanche all rely on a proof-of-stake mechanism.