You can build different kinds of websites/ web apps.

Specifically, there are three major types you can differentiate:

• Static Websites (just HTML + CSS + JS)

• Single-Page-Applications (SPAs, HTML + CSS + JS with only one HTML page being served, client-side JS is used to re-render the page dynamically)

• Dynamic/ Server-side rendered Web Applications: Websites where the HTML pages are created dynamically on the server (e.g. via templating engines like EJS).

You find a more detailed comparison here: https://academind.com/learn/web-dev/dynamic-vs-static-vs-spa/

When deploying such websites, it's important to understand that sites with NO server-side code (i.e. Static Websites and SPAs), required only a static host (e.g. AWS S3, Firebase Hosting).

Pages where HTML is generated dynamically on the server require a host that is capable of executing the server-side code (i.e. a server that supports NodeJS, PHP or whatever language is being used).