Besides already mentioned collateralized loans, there is another type of loan, which I think is impossible with traditional finance. It's Flash Loans. In this

Besides already mentioned collateralized loans, there is another type of loan, which I think is impossible with traditional finance. It's Flash Loans. In this case, you don't need to provide any collateral, but the smart contract is designed so that you cannot avoid repayment. It's just an atomic operation, like with database, where all of the actions happen, including repayment, or nothing at all. You can do that with defi. It's used for market arbitrage, or maybe to restructure other loans, etc.