What is Race and ethnicity in censuses?

Many countries and national censuses currently enumerate or have previously enumerated their populations by race, ethnicity, nationality, or a combination of these characteristics. Different countries have different classifications and census options for race and ethnicity/nationality which are not comparable with data from other countries. In addition, many of the race and ethnicity concepts that appear on national censuses worldwide have their origins in Europe or in the views of Europeans, rather than in the views of the locals of these countries.