DApps (decentralized applications) are like traditional computer applications – except that their code is written in a Smart Contract. This means that all the data and logic that runs the application resides on the blockchain, not on a central server. For this reason, once the application or data is installed in the blockchain, no one really “owns” the application or data. So, in terms of centrality, they are different from normal applications that you download from the Internet or buy from an App Store.
What distinguishes dApps from regular applications is that they are permissionless (anyone can run them) and permanent (they will exist as long as the blockchain exists). Since they are permissionless, anyone can interact with the Smart Contract without passing through a central gateway. And because they are permanent, users (and other applications) know that they will reliably exist in the future. This means that each dApp is like a Lego brick, opening up a whole new world of application possibilities.
