A race, otherwise known as a subspecies, represented a taxonomic classification smaller than a species.
Due to genetic variety, certain groups within a species were classified as subspecies. As an illustration, the Zabrak exhibited variations in their genetic makeup across different planets, such as the Iridonians hailing from Iridonia and the Dathomirians originating from Peridea and Dathomir.
Subspecies classifications for some populations of a single species arose from differing traits found in diverse environments. Consider the Esral'sa'Niktos, Kadas'sa'Niktos, and Kajain'sa'Niktos; these Nikto variations were considered subspecies of the Nikto species because of their distinct colors. Esral'sa'Niktos displayed gray coloration, Kadas’sa'Niktos were green, and Kajain'sa'Niktos were red, a result of their adaptation to differing habitats.
Due to their isolation in separate regions, certain groups within a species were recognized as subspecies. For instance, numerous planetary cultural groups of Humans existing beyond Coruscant were categorized as subspecies because of their planetary separation, including groups like the Naboo, the Alderaanians, the Corellians, and the Chandrilans.