man and wife vs family

man and wife and family both are nouns.

Word	Noun	Adjective	Verb	Adverb
man and wife	Yes	No	No	No
family	Yes	No	No	No

As nouns, family is a hypernym of man and wife; that is, family is a word with a broader meaning than man and wife:

Other hypernyms of man and wife include family unit.

man and wife (noun)	family (noun)
two people who are married to each other	primary social group; parents and children
	people descended from a common ancestor
	a social unit living together
	(biology) a taxonomic group containing one or more genera
	a collection of things sharing a common attribute
	an association of people who share common beliefs or activities
	a loose affiliation of gangsters in charge of organized criminal activities
	a person having kinship with another or others