A blockchain dApp (decentralized application) is a distributed open source software application that runs on a peer-to-peer (P2P) network and is supported by a blockchain distributed ledger. Application data and records of operation are encrypted and a cryptographic token is required to access the application. A major advantage of dApps is that they are always accessible and do not have a single point of failure (SPOF).
dApps are similar in some ways to conventional apps and use the same technology to render a web page. An important difference, however, is that while a classical application is supported by a centralized database, a dApp is supported by a smart contract that is connected to a blockchain. Since a smart contract consists of the back-end only and is often only a small part of the whole dApp, creating a decentralized app on a smart contract system requires combining several smart contracts and employing third-party systems for the front-end.Content Continues Below
Currently, the most popular platform for dApp developers is Ethereum but other blockchain platforms, such as Cardano, Lisk, QTUM and NEO are also being used for dApp development.