What is Proof of Stake?
On September 15, 2022, Ethereum switched from a proof-of-work (opens in a new tab) (PoW) mechanism to a proof-of-stake (opens in a new tab) (PoS) mechanism because it improved security, energy usage, and implemented new solutions for scaling that would allow the Ethereum network to expand further.
Validators
In a PoS system, validators are chosen to create new blocks and validate transactions, often based on the amount of cryptocurrency they hold and are willing to "stake" as collateral. These validators are selected through various algorithims (like random selection or coin age) and are responsible for ensuring that the transactions in the block are valid. As a reward, validators earn transaction fees and, in some systems, additional cryptocurrency for their services.