user interface vs CLI

user interface and CLI both are nouns.

Word	Noun	Adjective	Verb	Adverb
user interface	Yes	No	No	No
CLI	Yes	No	No	No

As nouns, CLI is a hyponym of user interface; that is, CLI is a word with a more specific, narrower meaning than user interface:

user interface: (computer science) a program that controls a display for the user (usually on a computer monitor) and that allows the user to interact with the system
CLI: a user interface in which you type commands instead of choosing them from a menu or selecting an icon

Other hyponyms of user interface include command line interface, graphical user interface, GUI.

user interface (noun)	CLI (noun)
(computer science) a program that controls a display for the user (usually on a computer monitor) and that allows the user to interact with the system	a user interface in which you type commands instead of choosing them from a menu or selecting an icon