Decentralized finance (DeFi) refers to financial services built on public blockchains that operate without traditional intermediaries like banks, brokers, or payment processors. Instead of relying on a central institution to hold funds and approve transactions, DeFi uses smart contracts, which are self-executing programs on networks such as Ethereum and other smart contract platforms, to define rules and automate actions.
How DeFi works
In DeFi, users typically connect a crypto wallet to a decentralized application (dApp) and interact directly with smart contracts. These contracts can custody assets in escrow, calculate interest, swap tokens, or enforce collateral requirements, all according to transparent code. Because the logic is on-chain, many DeFi protocols are composable, meaning one application can plug into another, similar to building with open software libraries.
A common example is decentralized exchanges (DEXs), where users trade tokens from their wallets using automated market makers rather than a centralized order book. Another example is lending and borrowing, where users supply assets to a protocol to earn yield, while borrowers take loans by posting collateral, with liquidation mechanisms triggered automatically if collateral falls below required thresholds.
Benefits, trade-offs, and risks
DeFi can expand access by allowing anyone with an internet connection and a compatible wallet to use financial tools, often with fewer gatekeepers. It can also improve transparency, since transactions and contract states are publicly verifiable. However, DeFi introduces new risks, including smart contract bugs, protocol governance attacks, oracle failures, liquidity shocks, and user errors like sending funds to the wrong address. Many users also face challenges around fees, network congestion, and complex interfaces.
Why DeFi matters
DeFi matters because it experiments with an open, programmable financial layer where rules are enforced by code and participation is broadly accessible, influencing how future digital financial systems may be built.