Something racial is related to the characteristics people have because of their genetic or ethnic origins. Racial differences sometimes lead to racial tension.
Members of the same racial group share a very old genetic connection — their ancestors lived in the same part of the world, and they're distantly related. When people talk about "racial diversity," they mean that many of these groups are represented, for example, in a single city. The noun race is at the heart of the adjective racial, and it comes from Old French, with an Italian root word, razza, "race, breed, lineage, or family."