Question: The most of "decentralized applications" are a "web" application as follows :

```
Front End (usually JavaScript) => Smart Contract (usually Solidity) => Blockchain (usually Ethereum)

```

**Is this the only schema of a Dapp?** And if there is other schema, could you describe another schema of a Dapp?

Answer: 
Well, the the [Mist Browser](https://github.com/ethereum/mist) is trying to be something in between: A standalone app for browsing dApps and thus making then feel a little like a desktop application.
You can use electron.js. I haven't tried it yet. [Here's a link to it](https://www.electronjs.org/)