I am seeking the definition of race and ethnicity and the difference between the two. Why are they so often used interchangeably in our society?
You are correct, the two words are often used interchangeably, though by definition they carry different meanings. In the simplest terms, race is used to describe genetic heritage (including one's skin color, and associated traits), while ethnicity describes one's cultural background or allegiance.
For more specific information about racial and ethnic groups, consult our almanac chapter on Race and Ethnicity.
—The Fact Monster