independent agency vs bureau

independent agency and bureau both are nouns.

Word	Noun	Adjective	Verb	Adverb
independent agency	Yes	No	No	No
bureau	Yes	No	No	No

As nouns, bureau is a hypernym of independent agency; that is, bureau is a word with a broader meaning than independent agency:

independent agency: an agency of the United States government that is created by an act of Congress and is independent of the executive departments
bureau: an administrative unit of government

Other hypernyms of independent agency include agency, authority, federal agency, government agency, office.

independent agency (noun)	bureau (noun)
an agency of the United States government that is created by an act of Congress and is independent of the executive departments	furniture with drawers for keeping clothes
	an administrative unit of government