coffee bar vs coffee shop

coffee bar and coffee shop both are nouns.

Word	Noun	Adjective	Verb	Adverb
coffee bar	Yes	No	No	No
coffee shop	Yes	No	No	No

As nouns, coffee bar and coffee shop are synonyms defined as:

coffee bar and coffee shop: a small restaurant where drinks and snacks are sold

Other synonyms of coffee bar include cafe, coffeehouse.

coffee bar (noun)	coffee shop (noun)
a small restaurant where drinks and snacks are sold	a small restaurant where drinks and snacks are sold