CVX is the native platform token for Convex Finance. CVX can be staked on the Convex protocol to earn Boosted CRV earnings.

Convex is a DeFi protocol built on top of Curve to facilitate higher returns for liquidity providers and CRV stakers. Convex Finance allows users to maximize their DeFi yields by allowing users to get the same boosted CRV rewards without having to lock up their assets for the entire duration of the staking period. When users deposit CRV into Convex, users are given cvxCRV, a tokenized version of veCRV, in return at a 1:1 rate.

Furthermore, Convex Finance is the single largest holder of veCRV, meaning that Convex has significant voting influence over Curve. CVX is used to vote on how Convex Finance will use the protocol’s holdings of veCRV to vote on how CRV inflation is distributed.

More information here