DeFi, short for decentralised finance, is lending, borrowing, trading and earning interest done by software on a public blockchain instead of by a bank. No branch, no account application, no credit check. You connect a wallet and use it. That's the whole idea. The jargon comes later.

Who holds the money

At a bank, the bank holds your deposit and decides what happens to it. It sets your savings rate, picks who gets a loan, and settles the paperwork days later. You trust the institution to stay honest and solvent.

In DeFi a smart contract does the job. Its rules, how much collateral a loan needs, what the interest rate is, when a loan gets liquidated, are written in code anyone can read. It treats every wallet the same, at 3am on Christmas Day as much as on a Tuesday.

A bank loan versus a DeFi loan: who sits in the middle TRADITIONAL Your deposit Bankdecides, holds, settles Borrower DEFI Your wallet Smart contractpublic rules, same for all Borrower's wallet
Same loan, different middleman. In DeFi the middle is code you can read, not a company you have to trust.

⚠ Red flag

That's a trade, not a free upgrade. Code can have bugs. Public code isn't the same as audited code. When the Ronin bridge was drained of about $625 million in March 2022, there was no fraud department to ring. "Trustless" means the risk moves from a company to the code and the economics behind it. It doesn't vanish.

Prefer to watch? The short version in 43 seconds.

AI presenter. Written by Robert Stone. More in our DeFi Explained for Beginners playlist.

What DeFi actually covers

  • Decentralised exchanges (DEXs). Swap tokens straight from your wallet, usually against a liquidity pool rather than an order book. Uniswap is the best known. Our guide to liquidity pools shows how the price gets set.
  • Lending and borrowing. Deposit crypto to earn interest, or lock some up as collateral and borrow against it. Aave and Compound are the big two.
  • Stablecoins. Tokens built to hold a dollar value, used as the everyday unit inside DeFi. Our stablecoins explainer covers how they hold the peg, and how they lose it.
  • Yield products. Strategies that move your deposit through several protocols to squeeze out a return. See yield farming explained.
  • Derivatives. On-chain futures, options and synthetic assets that track something without holding it.

Why it matters even if you never touch it

DeFi settles in minutes, not days. Anyone can build on top of it without asking permission. And it doesn't close. Those three things are why banks and asset managers now run their own experiments with tokenised funds and on-chain settlement. Whether DeFi ends up feeding traditional finance or competing with it is still being decided. The shift from institutions to open protocols is the part worth watching.

Starting without getting burned

Use small amounts first. Stick to protocols that have been running for years and have public audits. Write your seed phrase on paper and never type it into a website. And accept the one rule nobody can soften for you: your keys, your crypto, your mistake. There's no helpline.