Treasury Department vs Internal Revenue Service

Treasury Department and Internal Revenue Service both are nouns.

Word	Noun	Adjective	Verb	Adverb
Treasury Department	Yes	No	No	No
Internal Revenue Service	Yes	No	No	No

Treasury Department (noun)	Internal Revenue Service (noun)
the federal department that collects revenue and administers federal finances; the Treasury Department was created in 1789	the bureau of the Treasury Department responsible for tax collections