publisher vs publishing house

publisher and publishing house both are nouns.

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

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

Other synonyms of publisher include publishing company, publishing firm.

publisher (noun)	publishing house (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