Race does not exist physically; according to science, few genetic differences exist among humans, and race is not an appropriate diversity indicator. As a human-created classification system, race is considered a social construction. It was created to help people tell one another apart based on their physical characteristics, but it has instead been used to impose oppression and repression.
The construction of race helped those who were powerful, like the Whites, the dominant group. Individual racial classifications would remain stable across borders if race were real because genetics determines the existence of race. A person who is black in the United States may be viewed as white or colored in Brazil or South Africa.