sector vs social group

sector and social group both are nouns.

Word	Noun	Adjective	Verb	Adverb
sector	Yes	No	No	No
social group	Yes	No	No	No

As nouns, social group is a hypernym of sector; that is, social group is a word with a broader meaning than sector:

sector (noun)	social group (noun)
measuring instrument consisting of two graduated arms hinged at one end	people sharing some social relation
a particular aspect of life or activity
a social group that forms part of the society or the economy
a portion of a military position
the minimum track length that can be assigned to store information; unless otherwise specified a sector of data consists of 512 bytes
a plane figure bounded by two radii and the included arc of a circle