DeFi lets people swap tokens, lend or borrow through software on a blockchain. Smart contracts handle many tasks that banks or brokers would normally manage, but users still rely on code, governance and outside data. Ethereum’s DeFi overview provides additional background, including common uses and risks. Continue with related explainers in the BlockBriefing Learn hub.
What does DeFi mean?
Decentralized finance, commonly called DeFi, refers to financial applications that use blockchain networks and smart contracts to provide services such as swapping tokens, borrowing, lending or supplying liquidity. Instead of relying only on a central company to update an account ledger, users interact with software deployed on a blockchain. The level of decentralization varies from project to project.
What happens when you use a DeFi app
A smart contract is code deployed to a blockchain. It can enforce rules for a transaction when specified conditions are met. A DeFi application may combine several contracts, token standards and external data sources. Users typically connect a wallet and approve transactions, paying network fees. A transaction recorded on-chain may be difficult or impossible to reverse.
Common types of DeFi services
Decentralized exchanges allow users to swap tokens through smart-contract systems. Lending protocols may let users supply assets to pools and borrow against collateral. Liquidity providers contribute assets to trading pools and may earn fees, but can face impermanent loss and other risks. Some applications offer derivatives or yield strategies with additional complexity.
What decentralization does and does not mean
A protocol may publish its code and run on a public network, yet still rely on administrators, upgrade keys, oracles, front-end websites and concentrated governance. A user interface can be unavailable even if contracts remain on-chain. Read documentation to understand who can change the rules, pause a contract or control critical infrastructure.
The risks behind DeFi’s convenience
Risks include smart-contract bugs, compromised admin keys, malicious tokens, oracle failures, liquidation, phishing, network congestion and unexpected transaction costs. Audits can help identify issues but do not guarantee safety. High advertised yields may not be sustainable. Start by understanding each transaction, verify the website address and never share a seed phrase.
A safer research checklist
Read the project’s official documentation, check contract addresses through official channels, understand what permissions a wallet approval grants and test with a small amount if appropriate. Consider whether you can afford to lose the funds. This guide is educational and not a recommendation to use any particular protocol.
Frequently asked questions
Is DeFi completely trustless?
Not necessarily. Users may still depend on contract code, governance, oracles, interfaces and other infrastructure.
Can DeFi transactions be reversed?
Confirmed blockchain transactions are generally not reversible through a normal customer-support process.
Related Learn guides
Continue learning with these related explainers: What Is a Stablecoin? Types, Uses and Risks; Ethereum Gas Fees Explained: What You Pay and Why; How to Use a Blockchain Explorer.
Editorial note
Information is provided for educational purposes and can become outdated. Verify technical details against official documentation, understand the risks involved, and never share wallet recovery phrases or private keys.
