Is the app age rating a warning? I would like to know if the app age rating is a warning. This is a very simple question but the answer is important for me. For example, by default, will people under 17 be able to download an app whose age rating is +17?
Is it just a warning? Is it only forbidden to download with parental control or something?

I would be glad to know if someone can help me out.
https://www.bewebsmart.com/ipod-ipad-iphone/how-to-restrict-apps-by-rating/ 

If Parental Control restricts a certain age criteria, yes it can be a filter. There are filters like 9+, 13+ etc. If all apps are allowed by the admin, no warning will be seen on the basis of age restriction. It will be just metric to judge content of the app.