Proof of Stake is a blockchain consensus method that uses validators instead of miners. Validators lock or stake coins to help secure the network and confirm blocks.
How Proof of Stake differs from mining
In proof of work, miners spend computing power. In proof of stake, validators risk staked coins. If they act badly, they can lose rewards or be penalized.
Why networks use it
Proof of Stake can use less energy than mining and may allow faster finality. It is used by networks such as Ethereum, Solana, Cardano, and many others.
It still has tradeoffs, including validator concentration, staking rules, lockups, and governance questions.