◈ GLOSSARY · CRYPTO & WEB3
Smart Contract.
A definition, in plain English — with the books that teach it.
Reviewed by ClearValue Editorial Team · Jun 27, 2026
◈ DEFINITION
What it means
Definition
A program that lives on a blockchain and automatically executes when its conditions are met — no middleman, no 'pending review.' Ethereum popularized them; they're how DeFi, NFTs, and most non-Bitcoin crypto apps actually work. The honest caveat: 'code is law' cuts both ways — if the contract has a bug, the bug executes too, and there's usually no customer-support line to unwind it.
◈ IN PRACTICE
Example
A simple DeFi lending contract holds your ETH as collateral and lets you borrow USDC against it. If the value of your ETH drops below a set threshold, the contract automatically liquidates your collateral — no human approval, no grace period. That's the design, not a bug.