How does React js interact with the server?

Question

JavaScript

How does React interact with the server?
That is, there is a running React, and this React itself works there and exchanges data with the server via ajax requests?
That is, React works on npm, and some php c apache thread is spinning in parallel and react communicates with the php server via ajax without embedding php code in React
. I can’t explain it more precisely because I don’t really know react.
UPD. Not npm but Node

Answer 1

react works in the browser, interacts with the server "like normal sites", the react project is going to the usual pair of html/css/js files
in general yes

Answer 2

There is a react - this is a front-end server and there is, for example, a JSON-server or a server with a database. i.e. two servers