Aave (formerly LEND) is a decentralized finance (DeFi) protocol running on the Ethereum blockchain. Aave allows users to lend, borrow and store their tokens in liquidity pools.

Using smart contracts and a number of technological innovations, the Aave protocol allows users to borrow and lend safely and quickly. Aave offers lending and borrowing services in many different cryptocurrencies in exchange for users providing certain collateral.

Aave also allows users to earn interest by participating in liquidity pools. Users can earn interest by participating in liquidity pools with different cryptocurrencies. These pools are used for borrowing and lending by other users.

The Aave protocol takes various measures to ensure the security of lenders' collateral when users lend money to other users. These measures include methods such as storing the collaterals in a separate pool and automatically liquidating them if the value of the collaterals falls below a certain level.

Aave also offers a unique feature to its users: instant borrowing known as "flash loan". This feature allows users to borrow and repay in one block. During this process, the borrower is not required to provide collateral, but the borrowing must be completed in the same block.

In conclusion, Aave is a decentralized finance (DeFi) protocol running on the Ethereum blockchain and offers a range of services such as borrowing, lending and participating in liquidity pools. Aave also offers users the opportunity to borrow instantly with its flash loan feature.