Frax Finance is a DeFi platform that offers a variety of stablecoins, including the fractional-algorithmic stablecoin Frax and the CPI-pegged stablecoin FPI, as well as a liquid staking derivative called frxETH that can be staked as sfrxETH. The platform is built on the Ethereum blockchain and aims to provide users with stable, secure, and transparent financial products and services.