A set of categories used to distinguish subgroups of a larger society. The categories used have varied over time and in different societies. In the US, categories used for the 2000 Census refer to both race (based on physical characteristics) and ethnicity (based on cultural characteristics such as common language or religious tradition). The Census Bureau distinguishes Hispanics (who can be of any race group) from non-Hispanics, and simultaneously distinguishes five race groups: White, Black or African-American, Asian, American Indian and Alaskan Native, Native Hawaiian and Pacific Islander. Much social research combines this information into a set of race-ethnic categories, typically distinguishing White non-Hispanics, Black non-Hispanics, and Hispanics. Race itself, however, does not have taxonomic significance in biology with regard to humans who all belong to the same species (viz., Homo sapiens).
See General theory of biological classification, Eugenics, Socioeconomic status, Species, Typological thinking