Intersectionality (or intersectional theory) is the study of overlapping or intersecting social identities and related systems of oppression, domination or discrimination. The theory suggests that—and seeks to examine how—various biological, social and cultural categories such as gender, race, class, ability, sexual orientation, religion, caste, age and other axes of identity interact on multiple and often simultaneous levels. This framework can be used to understand how systemic injustice and social inequality occur on a multidimensional basis. Intersectionality holds that the classical conceptualizations of oppression within society—such as racism, sexism, classism, ableism, biphobia, homophobia, transphobia, and belief-based bigotry—do not act independently of each other. Instead, these forms of oppression interrelate, creating a system of oppression that reflects the "intersection" of multiple forms of discrimination.