British vs British people

British and British people both are nouns.

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

As nouns, British and British people are synonyms defined as:

Other synonyms of British include Brits.

British (noun)	British people (noun)
the people of Great Britain	the people of Great Britain

British (adjective)	British people (adjective)
of or relating to or characteristic of Great Britain or its people or culture