age bracket vs people

age bracket and people both are nouns.

Word	Noun	Adjective	Verb	Adverb
age bracket	Yes	No	No	No
people	Yes	No	Yes	No

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

age bracket: a group of people having approximately the same age
people: (plural) any group of human beings (men or women or children) collectively

age bracket (noun)	people (noun)
a group of people having approximately the same age	(plural) any group of human beings (men or women or children) collectively
	the body of citizens of a state or country
	members of a family line
	the common people generally

age bracket (verb)	people (verb)
	fill with people
	furnish with people