Ethereum staking is a financial strategy involving the locking up of Ethereum (ETH) to support the operational security and integrity of the blockchain network. By staking ETH, participants, known as validators, contribute to the network's security and, in return, earn rewards derived from transaction fees and network incentives. This process is critical under Ethereum's Proof of Stake (PoS) model, which emphasizes energy efficiency and a lower barrier to entry compared to traditional mining.