By definition, diversity signifies no more than difference.
Items are diverse when they differ from one another.
In the context of multiculturalism, however, the difference that defines diversity centers on people of varying ethnic backgrounds. Diversity within multiculturalism, then, means specifically cultural diversity. And cultural diversity is not just exalted. To celebrate diversity requires that diverse cultures live in close proximity, with tolerance, and without assimilation. Celebrating diversity is a self-conscious practice.