human race vs humans

human race and humans both are nouns.

Word	Noun	Adjective	Verb	Adverb
human race	Yes	No	No	No
humans	Yes	No	No	No

As nouns, human race and humans are synonyms defined as:

Other synonyms of human race include human beings, humanity, humankind, man, mankind, world.

human race (noun)	humans (noun)
all of the living human inhabitants of the earth	all of the living human inhabitants of the earth