DeFi platforms are decentralized financial services built on blockchain technology that aim to replace traditional intermediaries such as banks. These platforms offer services like lending, borrowing, trading, and earning interest through liquidity pools, all without central control. DeFi platforms are powered by smart contracts that automatically execute transactions based on predefined rules. They provide users with more transparency, accessibility, and control over their assets. Popular DeFi platforms include Uniswap, Aave, and Compound, each offering unique services within the decentralized finance ecosystem.