demography vs sociology

demography and sociology both are nouns.

Word	Noun	Adjective	Verb	Adverb
demography	Yes	No	No	No
sociology	Yes	No	No	No

As nouns, sociology is a hypernym of demography; that is, sociology is a word with a broader meaning than demography:

demography: the branch of sociology that studies the characteristics of human populations
sociology: the study and classification of human societies

demography (noun)	sociology (noun)
the branch of sociology that studies the characteristics of human populations	the study and classification of human societies