DApps are applications that run on a decentralized network, typically a blockchain, rather than being hosted on centralized servers. They often interact with smart contracts and provide a user interface for blockchain functionality. Web3 developers, designers, and product managers commonly use this term. To excel in DApp development, one should be proficient in both front-end technologies (like React.js) and blockchain interaction libraries (like web3.js or ethers.js), as well as understand the unique UX challenges of decentralized systems.