Aave is a decentralized non-custodial liquidity protocol where users can participate as depositors or borrowers. Depositors provide liquidity to the market to earn a passive income, while borrowers are able to borrow in an overcollateralized (perpetually) or undercollateralized (one-block liquidity) fashion.

Aave pioneered the concept of flash loans in DeFi — uncollateralized loans that must be repaid within a single transaction block.