Lido Staked ETH is a tokenized representation of Ethereum (ETH) that has been deposited into the Lido protocol for staking. By staking ETH with Lido, users can earn rewards on their holdings while maintaining liquidity and flexibility to trade or use their staked ETH in decentralized finance (DeFi) applications. This allows users to participate in Ethereum's proof-of-stake network and earn staking rewards without having to lock up their ETH for an extended period of time.