desktop vs CRT screen

desktop and CRT screen both are nouns.

Word	Noun	Adjective	Verb	Adverb
desktop	Yes	No	No	No
CRT screen	Yes	No	No	No

As nouns, CRT screen is a hypernym of desktop; that is, CRT screen is a word with a broader meaning than desktop:

desktop: (computer science) the area of the screen in graphical user interfaces against which icons and windows appear
CRT screen: the display that is electronically created on the surface of the large end of a cathode-ray tube

Other hypernyms of desktop include screen.

desktop (noun)	CRT screen (noun)
(computer science) the area of the screen in graphical user interfaces against which icons and windows appear	the display that is electronically created on the surface of the large end of a cathode-ray tube
the top of a desk