DApp (Decentralized Application)

A DApp, or decentralized application, is a piece of software whose core logic runs on a blockchain instead of on servers owned by one company. Rather than trusting a central operator to store data and enforce rules, a DApp delegates those jobs to smart contracts deployed on-chain, code that executes exactly as written and cannot be quietly altered, paused, or censored by a single party once it goes live.

Most DApps combine three layers: a blockchain backend that stores state and processes transactions, one or more smart contracts that encode the application's rules, and a frontend, often an ordinary website or mobile interface built with familiar tools like JavaScript, that lets users interact with the contract. Users typically connect a crypto wallet to sign transactions, and every action, a swap, a vote, a bid, is recorded on the ledger rather than in a private database.

The concept spans far beyond finance. Well-known examples include the decentralized exchange Uniswap, the NFT marketplace OpenSea, and games like Axie Infinity and Decentraland, where in-game assets and land exist as tokens the player actually owns. Governance of a DApp is sometimes handed to its community through a DAO, and many DApps store large files off-chain on networks like IPFS while keeping only critical logic and ownership records on the blockchain itself, most commonly Ethereum and its layer-2 networks.

Because smart contract code is difficult to change after deployment, bugs or exploits can be costly, and unlike a traditional app, there is rarely a company able to reverse a transaction or offer a refund.