Does my remote server (Amazon EC2) need 2 different servers running to run EmberJS and Spring Boot?

It seems that for EmberJS we need a server to run, usually on localhost:4040.

Spring Boot needs its own server for run of coarse on localhost:8080.

Is this really necessary to run 2 different servers on a remote server or even recommended?

Why can't I just get the javascript from the EmberJS and put it in my Spring Boot project. As in go to the static resources folder and put the EmberJS files there?

Why do we really need a server for EmberJS in the first place? It's front end code to be read by a browser?

If none of this is recommended then how do we use EmberJS and Spring Boot together on one server? Everywhere I see uses EmberJS on its own server and does a cross request to localhost:8080 for spring boot.

I am relatively new to Web App Dev so some jargon may go over my head.