Third gender or third sex is the concept that individuals are categorized, either by themselves or by society, as neither man nor woman. It also describes a social category present in those societies that recognize three or more genders. The term third is usually understood to mean "other"; some anthropologists and sociologists have described fourth, fifth, and "some" genders. The concepts of "third", "fourth" and "some" genders can be somewhat difficult to understand within Western conceptual categories.