Beacon Chain:

The Beacon Chain is the backbone of Ethereum 2.0. It is responsible for managing the PoS protocol, keeping track of validators, and ensuring the overall network’s consensus. It went live in December 2020 and is crucial for the full transition.
Staking:

Under PoS, users can lock up their ETH in the network as a form of collateral (staking). In return, they participate in validating transactions and securing the network. This process helps secure Ethereum in a more energy-efficient way compared to PoW.