Linux Hint published a tutorial about installing the XFCE desktop on Debian 11.
Install XFCE Desktop on Debian 11
Linux and its distributions support a variety of desktop environments; with the help of the desktop environments, users can experience more than one desktop interface. Linux provides extensive support for several desktop environments like: GNOME, KDE 5, Unity, LXQt, XFCE. This article explains how to install the lightweight desktop environment XFCE on Debian 11 Bullseye.