desktop vs screen background

desktop and screen background both are nouns.

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

As nouns, desktop and screen background are synonyms defined as:

desktop and screen background: (computer science) the area of the screen in graphical user interfaces against which icons and windows appear

Other synonyms of desktop include background.

desktop (noun)	screen background (noun)
(computer science) the area of the screen in graphical user interfaces against which icons and windows appear	(computer science) the area of the screen in graphical user interfaces against which icons and windows appear
the top of a desk