publishing company vs publisher

publishing company and publisher both are nouns.

Word	Noun	Adjective	Verb	Adverb
publishing company	Yes	No	No	No
publisher	Yes	No	No	No

As nouns, publishing company and publisher are synonyms defined as:

Other synonyms of publishing company include publishing firm, publishing house.

publishing company (noun)	publisher (noun)
a firm in the publishing business	a firm in the publishing business
	a person engaged in publishing periodicals or books or music
	the proprietor of a newspaper