Sunni vs religious sect

Sunni and religious sect both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sunni	Yes	No	No	No
religious sect	Yes	No	No	No

As nouns, religious sect is a hypernym of Sunni; that is, religious sect is a word with a broader meaning than Sunni:

Other hypernyms of Sunni include religious order, sect.

Sunni (noun)	religious sect (noun)
one of the two main branches of orthodox Islam	a subdivision of a larger religious group
a member of the branch of Islam that accepts the first four caliphs as rightful successors to Muhammad