art vs graphic art

art and graphic art both are nouns.

Word	Noun	Adjective	Verb	Adverb
art	Yes	No	No	No
graphic art	Yes	No	No	No

As nouns, graphic art is a hyponym of art; that is, graphic art is a word with a more specific, narrower meaning than art:

art (noun)	graphic art (noun)
the creation of beautiful or significant things	the arts of drawing or painting or printmaking
the products of human creativity; works of art collectively
a superior skill that you can learn by study and practice and observation
photographs or other visual representations in a printed publication