Debian Desktop Environment in Installer

If no specific desktop environment is selected, but the “Debian desktop environment” is, the default which ends up installed is determined by tasksel: on i386 and amd64, it’s GNOME, on other architectures, it’s XFCE.

The Debian-desktop-environment option appears to add distro branding (additional info in details-of-packages linked below); also, as mentioned, GNOME is installed by default -- unless another DE is selected.

Package: desktop-base (9.0.2+deb9u1) common files for the Debian Desktop

This package contains various miscellaneous files which are used by Debian Desktop installations. Currently, it provides some Debian-related artwork and themes, .desktop files containing links to Debian related material (suitable for placement on a user's desktop), and other common files between the available desktop environments such as GNOME and KDE.

Package: task-desktop (3.39) Debian desktop environment

This task package is used to install the Debian desktop.