What is a Dapp?
Decentralized applications are a piece of software that communicates with the blockchain/Network ie. Tron Network, Binance Smart Chain, XRP Ledger, Bitcoin Blockchain, Ethereum Network Terra Luna Network, EGold and so many more, which manages the state of all network actors. The interface of the decentralized applications does not look any different than any website or mobile app today. The smart contract represents the core logic of a decentralized application. Smart contracts are integral building blocks of blockchains, that process information from external sensors or events and help the blockchain manage the state of all network actors.
The frontend of a decentralized application represents what you see, and the backend represents the entire business logic. This business logic is represented by one or several smart contracts interacting with the underlying blockchain. The frontend, as well as files like a photo, a video, or audio, could be hosted on decentralized storage networks such as Swarm or IPFS. Traditional Web applications use HTML, CSS, and javascript or the like to render a webpage. This page interacts with a centralized database, where all the data is stored. When you use a service like Twitter, Facebook, Amazon, or Airbnb, for example, the webpage will call an API to process your personal data and other necessary information stored on their servers, to display them on the page. User ID and passwords are used for identification and authentication, with low levels of security, since personalized data is stored on the server of the service provider.
To make it simple Blockchain Networks are new Internets some are separated but eventually they will all merge into one larger network making an Ultra internet of Value!