Definition - What does Binary Gender mean?
The gender binary is the grouping of gender into two forms which are considered not only distinct but completely opposite from each other: male and female. The gender binary dictates that all people fall into one of these two categories and calls for them to dress and act as one or the other side of the binary. Generally people who are born with penises are assumed to align with the masculine side while people born with vulvae are assumed to align with the feminine side. The gender binary is dangerous as it erases all other gender options.
Kinkly explains Binary Gender
The gender binary or gender binarism can be seen everywhere. Starting in infancy when babies born with penises have their rooms painted blue and babies with vulva have theirs painted pink and continuing through adulthood when we encounter forms that ask respondents for their gender and offer the options "male" and "female."