rswETH is an ERC-20 Liquid Restaking Token that provides liquidity for users who are wanting to "restake" their ETH into restaking protocols such as EigenLayer without having their restaked ETH locked.
It is a repricing token that represents a user's yield-bearing ETH that is being used by validators that attest to transactions on the Ethereum blockchain.
To "restake" is to have a validator that has their withdrawal credentials pointed to an Eigenlayer Eigenpod address.