people vs sept

people and sept both are nouns.

Word	Noun	Adjective	Verb	Adverb
people	Yes	No	Yes	No
sept	Yes	No	No	No

As nouns, sept is a hypernym of people; that is, sept is a word with a broader meaning than people:

Other hypernyms of people include family, family line, folk, kinfolk, kinsfolk, phratry.

people (noun)	sept (noun)
(plural) any group of human beings (men or women or children) collectively	people descended from a common ancestor
the body of citizens of a state or country
members of a family line
the common people generally

people (verb)	sept (verb)
fill with people
furnish with people