family vs family unit

family and family unit both are nouns.

Word	Noun	Adjective	Verb	Adverb
family	Yes	No	No	No
family unit	Yes	No	No	No

As nouns, family and family unit are synonyms defined as:

family (noun)	family unit (noun)
primary social group; parents and children	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