Systems of oppression are individual, institutional, and societal and their effects on people have a long history deeply rooted in American culture.
Whether we are aware of it or not, we are all assigned multiple social identities. Within each category, there is a hierarchy - a social status with dominant and non-dominant groups. As with race, dominant members can bestow benefits to members they deem "normal," or limit opportunities to members that fall into "other" categories.
A person of the non-dominant group can experience oppression in the form of limitations, disadvantages, or disapproval. They may even suffer abuse from individuals, institutions, or cultural practices. "Oppression" refers to a combination of prejudice and institutional power that creates a system that regularly and severely discriminates against some groups and benefits other groups.