The proof-of-stake (PoS) consensus mechanism utilizes validators to verify transactions and maintain consensus in a blockchain network. The network incentivizes users to run validator nodes and stake their coins, which helps secure the network in return for earning interest on their stake.

There are some variations as to how PoS systems work depending on which protocol, but generally, the algorithm chooses blocks at random and assigns them to a validator node for review. The validator then checks the legitimacy of the transactions. If everything is accurate, the validator adds the block to the ledger and receives the block rewards and transaction fees. However, if a validator adds a block with the wrong data, its staked holdings will be penalized.

PoS is known for its superior energy efficiency, lower barriers to entry, and better scalability to PoW. In fact, the Ethereum PoS model also offers stronger support for shard chains, one of the most promising scaling solutions to date.