Binary opposition means that things can be divided into two opposite categories or concepts. It's like having two choices: you can either be this or that, but you can't be both at the same time.
Think of it like sorting things into groups, but instead of having many groups, you only have two. For example, you might sort animals into two groups: those with fur and those without fur. Or, you might sort colors into two groups: light and dark colors.
In literature, binary opposition is often used to create conflict or tension between two opposite characters or ideas. One character might represent one side of the binary, while another character represents the opposite side. For example, in the Harry Potter books, Harry represents the good side, while Voldemort represents the evil side.
Overall, binary opposition is like dividing things into two opposite categories, which is often used in literature to create tension between characters or ideas.