dApp (decentralised application)

A dApp, or decentralised application, is an app whose core logic runs on smart contracts on a blockchain rather than on a company's private servers. Uniswap, Aave and OpenSea are well-known examples.

You use a dApp by connecting a self-custody wallet, such as MetaMask, Phantom or a mobile wallet, to its website. When you take an action, like swapping tokens, the dApp prepares a transaction and your wallet asks you to approve and sign it. The smart contract then executes on-chain, and your assets stay in your own wallet rather than an account controlled by the app.

Most dApps are only partly decentralised: the website you visit, the data indexers and sometimes the ability to upgrade the contracts are controlled by a team. Because transactions are irreversible and contracts can contain bugs, always check you are on the correct website, read what your wallet asks you to sign, and be cautious about granting unlimited token approvals.