Marinade.Finance is a non-custodial liquid staking protocol built on Solana. You can stake your SOL tokens with Marinade using automated staking strategies and receive "marinated SOL" tokens (mSOL) that you can use in decentralized finance (DeFi). The price of mSOL goes up relative to SOL each epoch with rewards being accrued into the underlying staked SOL.
Marinade offers you the possibility to stake your SOL in exchange for mSOL that you can use in DeFi while still enjoying the staking rewards. The SOL that you are staking with Marinade is spread among more than 450 validators, excluding the so-called "security group" (top 19 validators).