affinity vs family relationship

affinity and family relationship both are nouns.

Word	Noun	Adjective	Verb	Adverb
affinity	Yes	No	No	No
family relationship	Yes	No	No	No

As nouns, family relationship is a hypernym of affinity; that is, family relationship is a word with a broader meaning than affinity:

affinity: (anthropology) kinship by marriage or adoption; not a blood relationship
family relationship: (anthropology) relatedness or connection by blood or marriage or adoption

Other hypernyms of affinity include kinship, relationship.

As nouns, family relationship is a hypernym of affinity; that is, family relationship is a word with a broader meaning than affinity:

affinity: (biology) state of relationship between organisms or groups of organisms resulting in resemblance in structure or structural parts
family relationship: (anthropology) relatedness or connection by blood or marriage or adoption

Other hypernyms of affinity include kinship, relationship.

affinity (noun)	family relationship (noun)
inherent resemblance between persons or things	(anthropology) relatedness or connection by blood or marriage or adoption
a natural attraction or feeling of kinship
the force attracting atoms to each other and binding them together in a molecule
(immunology) the attraction between an antigen and an antibody
(anthropology) kinship by marriage or adoption; not a blood relationship
(biology) state of relationship between organisms or groups of organisms resulting in resemblance in structure or structural parts
a close connection marked by community of interests or similarity in nature or character