What is DeFi?

Plain-English explainer · Updated 2026-05-03 · By DeFi Intel

Last reviewed 2026-05-03

Entity coverage: 3 protocols, 0 tokens, 1 chain reference this concept.

Decentralized finance refers to financial services (lending, trading, derivatives, insurance, asset management) implemented as smart contracts on public blockchains. DeFi removes intermediaries, settles 24/7 globally, and is composable: any protocol can integrate with any other.

Total value locked peaked above $200B in 2021 and stabilized around $100-150B by 2026 across Ethereum, Solana, BSC, Tron, Base, Arbitrum, and TON.

How it works

A DeFi interaction follows the same basic loop regardless of protocol. First, a user connects a self-custodial wallet and signs a transaction with their private key — there is no account signup, and the protocol never takes custody of the key. The transaction calls a function on a smart contract: deposit into a lending pool, swap against a liquidity pool, mint a stablecoin against collateral. Before assets can move, an ERC-20 style approval grants the contract permission to pull a specific token amount.

The contract then executes deterministically: it checks balances and collateral ratios, reads prices from oracles where needed, updates its internal ledger, and emits events that indexers and frontends read. Validators include the transaction in a block, and every node re-executes it, so the result is enforced by consensus rather than by a company.

Because every contract exposes public functions, protocols compose: a yield aggregator can deposit into a lending market that accepts a liquid staking token as collateral, all in one transaction. Interest rates, swap prices, and liquidation thresholds are set algorithmically by contract code, with parameters typically adjusted through token-holder governance.

Why it matters

DeFi removes intermediaries, settles 24/7 globally, and is composable — any protocol integrates with any other. It is the largest non-payment use case for crypto with $100B+ TVL.

Real-world examples

Aave (lending), Uniswap (DEX), MakerDAO (stablecoin issuance), Lido (liquid staking), Pendle (yield trading).

Related terms

Go deeper

Browse the complete crypto glossary to explore related terms and concepts.

Browse Glossary

Frequently asked questions

What is DeFi in simple terms?

Decentralized finance refers to financial services (lending, trading, derivatives, insurance, asset management) implemented as smart contracts on public blockchains, removing intermediaries and settling 24/7 globally.

How does a DeFi interaction work?

A user connects a self-custodial wallet, signs a transaction with their private key, and calls a function on a smart contract, which executes deterministically by checking balances and collateral ratios, reading prices from oracles, and updating its internal ledger.

What are some real-world examples of DeFi protocols?

Real-world examples include Aave (lending), Uniswap (DEX), MakerDAO (stablecoin issuance), Lido (liquid staking), and Pendle (yield trading).