submenu vs computer menu

submenu and computer menu both are nouns.

Word	Noun	Adjective	Verb	Adverb
submenu	Yes	No	No	No
computer menu	Yes	No	No	No

As nouns, computer menu is a hypernym of submenu; that is, computer menu is a word with a broader meaning than submenu:

submenu: a secondary menu that appears while you are holding the cursor over an item on the primary menu
computer menu: (computer science) a list of options available to a computer user

Other hypernyms of submenu include menu.

submenu (noun)	computer menu (noun)
a secondary menu that appears while you are holding the cursor over an item on the primary menu	(computer science) a list of options available to a computer user