Emacs allows you to open multiple windows that share the same local server / process and essentially work as one editor.

You can open the same or different files in the different views, use one of the views for debugging, shells, remotely running tests, while you use the other views for other stuff (showing different files side-by-side, etc.).

I often see vim and vs code users doing a lot of shuffling around when working with multiple open files to switch back and forth between files or across tabs, but with emacs none of this is really necessary.