Decentralized applications, or dApps, are software applications that run on a blockchain network rather than a single server. This means they are not controlled by any central authority, making them more resistant to censorship and downtime. Users interact with dApps through smart contracts, which are self-executing agreements coded into the blockchain. dApps can serve various purposes, including finance, gaming, and social networking. They often use cryptocurrencies for transactions, allowing users to maintain control over their data and assets. Popular examples of dApps include Uniswap for trading and CryptoKitties for digital collectibles.