DApp is an abbreviated form for decentralized application.
A DApp has its backend code running on a decentralized peer-to-peer network.
Contrast this with an app where the backend code is running on centralized
servers.
A DApp can have frontend code and user interfaces written in any language (just
like an app) that can make calls to its backend. Furthermore, its frontend can
be hosted on decentralized storage such as Swarm or IPFS.
For an application to be considered a Dapp (pronounced Dee-app, similar to
Email) it must meet the following criteria: