A DApp (Decentralized Application) is an application that runs on a distributed blockchain network rather than a single centralized server. DApps combine smart contracts on the backend with a user interface on the frontend.
Characteristics of DApps include open-source code, decentralized backend on blockchain, token-based incentives, and no single point of failure.
Popular DApp categories include DeFi (Uniswap, Aave), NFT marketplaces (OpenSea), Gaming (Axie Infinity), Social platforms (Lens Protocol), and DAOs (governance platforms).
Advantages of DApps include censorship resistance, no downtime, trustless interactions, user data ownership, and transparent operations. Challenges include scalability and user experience complexity.