Android is the default mobile operating system that you can use on the go. Debian is available as an app that you can load in Android, allowing you to switch to a GNU/Linux distro with support for desktop apps at any time. And Windows 11 is installed alongside Android in a dual boot configuration, allowing you to switch operating systems when you want to use your Android phone as a Windows desktop.

You can already do the linux part with any android phone with apps like this: https://f-droid.org/hu/packages/tech.ula/