What is a dApp (decentralized application)?

A dApp is an application whose logic runs on a blockchain via smart contracts — usually a combination of several contracts — rather than on a company's centralized servers.

In a traditional app, the logic and data live on servers that one company controls and can change or shut off. A decentralized application (dApp) instead runs its core logic as smart contracts on a decentralized network, so no single operator can censor it, alter its rules, or take it down. A dApp is typically not one contract but a combination of many working together. Because the logic executes on a network of independent nodes, users interacting with a dApp get the blockchain's guarantees — transparency, immutability, and resistance to a central party flipping a switch. The terms "dApp," "protocol," and "smart contract platform application" are often used loosely for the same idea: software whose trust comes from decentralized code rather than a trusted company.

Go deeper:

• Introduction to dapps — ethereum.org — a dapp as a smart-contract backend plus a frontend, and why no single operator controls it.