A DAO (Decentralized Autonomous Organization) is an organization where decisions are made by smart contracts and token voting, not traditional hierarchy. Members hold governance tokens. Votes on proposals execute automatically (e.g., transfer funds from treasury, deploy code). Core components: token design (what incentivizes good governance?), voting mechanics (how to vote fairly?), treasury (where's the money?), execution (how do approved decisions happen?), and dispute resolution (what if someone cheats?).