StETH is the tokenized version of staked Ether launched in December 2020 by Lido.fi. The Lido platform offers a liquid staking solution for Ethereum and other proof of stake coins. It means that via Lido users can stake tokens without locking them and can also receive daily rewards.
Lido makes the ETH coins liquid and enables users to participate with any amount of Ethereum. stETH owners will receive staking rewards from ETH 2.0 and see their balance updated every day at 12pm UTC. Lido-staked ETH can be used for the same purposes as Ethereum. You can sell it, use it for payments, or as collateral for on-chain lending.
Lido is famous for its staked Ethereum tokens but the company is now actively working with other blockchains too. For example, in March 2021 the bLuna derivative token was launched to allow staking Terra Luna via Lido. Later, in September 2021 the platform also released the stSOL token as the tokenized form of staked Solana.