Preface
This question regards Gnome [1]. Before proceeding any further, the reader should understand what Gnome is. One answer to this question, which is posted below by Henning Kockerbeck, suggest that I should look at a website to understand what Gnome is. Let me be clear, after getting 5 down votes, I went to Gnome.org. In my humble opinion, there is nothing there that spells out in simple terms what Gnome actually is. My best guess is that Gnome is not one thing at all, but rather several. Gnome appears to be a foundation; an amalgam of technologies [2] with which to use the Linux operating system; and a shell called GNOME shell. The latter is probably what is referred to by the applications gnome-3-38-2004 and gnome-42-2204 (see below).
Further, as suggested below, a more useful account can be obtained by Wikipedia [3]. There it states that,
GNOME Shell is the graphical shell of the GNOME desktop environment.... It provides basic functions like launching applications, switching between windows and is also a widget engine.
This quote is important to the question at hand because it appears---indeed---that this question is better rewritten as In principle I know what GNOME shell is; can I delete multiple instances of it?
Context
In a previous question [10], I asked about removing var and usr directories. The motivation was because I kept getting messages about low disk space in my root. In answer, Merilyn Ne referenced [20], which offers 10 Ways to Clean up Your
Ubuntu System to Free up Disk Space. Item 2 of 10 on the list is to removed remove unused applications. When I look at the list of installed applications, I do not know what some of them are and if I need them, or not.
Questions
(1) Can gnome be safely removed?
(2) If there are more than two gnome installed (e.g., gnome-3-38-2004 [362 MB] and gnome-42-2204 [430 MB]) can one, or both, be safely removed?
References
[2] https://www.gnome.org/technologies/
[3] https://en.wikipedia.org/wiki/GNOME_Shell
[10] should I delete var or usr directories
[20] https://fostips.com/clean-up-ubuntu-free-disk-space/
