upper side vs desktop

upper side and desktop both are nouns.

Word	Noun	Adjective	Verb	Adverb
upper side	Yes	No	No	No
desktop	Yes	No	No	No

As nouns, desktop is a hyponym of upper side; that is, desktop is a word with a more specific, narrower meaning than upper side:

Other hyponyms of upper side include crest, crown, poll, crown, pate, poll, rooftop, tiptop.

upper side (noun)	desktop (noun)
the highest or uppermost side of anything	(computer science) the area of the screen in graphical user interfaces against which icons and windows appear
	the top of a desk