common people vs people

common people and people both are nouns.

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

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

common people: people in general (often used in the plural)
people: (plural) any group of human beings (men or women or children) collectively

common people (noun)	people (noun)
people in general (often used in the plural)	(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

common people (verb)	people (verb)
	fill with people
	furnish with people