Client-side interface of a DApp can use standard web technologies (HTML, CSS, JavaScript, etc.).
Typically are used a JavaScript convenience libraries, that provide an API to make integrations with smart contract (backend) easier for developers.
By choosing hosting / domain for a DApp, there are options:
- centralized – standard hosting service (most likely in AWS, GC or Azure) / DNS
- decentralized – IPFS, Swarm / ENS