How to create a backend?

Question

Backend

I started learning web development, fully mastered the Frontend, I'm starting to learn php for the backend. But the question is: how to place the northern php scripts correctly - in the root directory or in a separate folder?

Answer 1

Sources ( src/), configs ( configs/) and other internals of the project should always be above or at the level of the directory ( public/) that is available to the web server, but never in it.

Answer 2

fully mastered Frontend

Come on!
I have not seen a single person in my life who has fully mastered the frontend.
Now I'll ask you a couple of questions on the front and you won't answer them :)
Let's start with Android and iOS. You will not deny that mobile applications are also front-end?

Answer 3

fully mastered Frontend

No, they didn't.

But the question is: how to place the northern php scripts correctly - in the root directory or in a separate folder?

It's not entirely clear what you mean? You usually have folders with sites on the server in the www folder, then all the files of the site are already inside. PHP, all modern frameworks usually place the entry file in the public folder. You can download any framework and see its structure (or just open some courses, usually one of the first lessons is the course structure).
In general, I would recommend that you take a look at PHP a little, maybe make some kind of shit blog, and continue to work on exactly the direction that you liked best.