DeFi is a blockchain-based financial ecosystem that replaces banks and intermediaries with smart contracts, enabling permissionless lending, borrowing, trading, and yield generation. Unlike traditional finance, DeFi runs 24/7 on decentralized networks like Ethereum and Solana, offering transparent, auditable, and automated financial services. Through decentralized exchanges (DEXs), lending protocols like Aave, and stablecoins such as USDC or DAI, users can earn yield, provide liquidity, or access crypto loans without relying on centralized entities. The core technologies—smart contracts, oracles, and composable protocols (“Money Legos”)—enable seamless interaction between different DeFi apps. DeFi brings financial inclusion, self-custody, and higher efficiency, but also carries risks like smart contract exploits, volatility, and systemic dependencies. It’s transforming finance with open-source innovation, tokenized assets, and cross-chain interoperability, shaping a new global financial paradigm.