suburb vs residential area

suburb and residential area both are nouns.

Word	Noun	Adjective	Verb	Adverb
suburb	Yes	No	No	No
residential area	Yes	No	No	No

As nouns, residential area is a hypernym of suburb; that is, residential area is a word with a broader meaning than suburb:

suburb: a residential district located on the outskirts of a city
residential area: a district where people live; occupied primarily by private residences

Other hypernyms of suburb include community, residential district.

suburb (noun)	residential area (noun)
a residential district located on the outskirts of a city	a district where people live; occupied primarily by private residences