Decentralized Application — an application that runs on a blockchain network rather than centralized servers.
A decentralized application (dApp) is software that runs on a blockchain or peer-to-peer network rather than being hosted on centralized servers controlled by a single company. dApps combine a traditional frontend (website or mobile app) with smart contract backends on blockchain. This architecture provides several advantages: censorship resistance (no single entity can shut down the app), transparency (code is open and verifiable), trustlessness (users interact with code, not companies), and composability (dApps can build on top of each other). Major categories of dApps include DeFi protocols (Uniswap, Aave), NFT marketplaces (OpenSea, Blur), gaming (Axie Infinity), social platforms (Lens Protocol), and DAOs (governance tools). The term 'dApp' is sometimes criticized as misleading — many dApps still rely on centralized frontends, APIs, and infrastructure, with only the core financial logic truly running on-chain.
Decentralized applications run on blockchain networks rather than centralized servers, meaning no single company controls the application or can censor users. The user experience of dApps has improved dramatically from early days — modern DeFi protocols, NFT marketplaces, and gaming platforms offer interfaces comparable to traditional web apps, albeit usually requiring a wallet connection. Key advantages of dApps include censorship resistance (no one can shut them down), composability (dApps can build on each other like Lego blocks), and transparency (code and transactions are publicly verifiable). Disadvantages include slower performance, higher costs (gas fees), and more complex user experiences (wallet management, gas estimation, transaction confirmation). The distinction between dApps and traditional apps is increasingly blurring as projects adopt hybrid architectures — using blockchains for settlement and ownership while handling computation off-chain for speed.
Uniswap is a dApp where the core trading logic (AMM smart contracts) runs entirely on Ethereum — even if the Uniswap Labs website went down, anyone could interact with the contracts directly or build a new frontend, because the protocol itself is permanent and permissionless.
Most dApps require a small amount of the blockchain's native token (ETH for Ethereum dApps, SOL for Solana dApps) to pay transaction fees (gas). Some newer dApps use account abstraction or gas sponsorship to cover fees for users, making the experience closer to traditional apps.