Let’s talk about gender. You understand the concept of binary, as in hot and cold or light and dark, and you understand that while we conceptually talk about, for example, hot and cold, we’re actually referring to a spectrum of heat, where “hotter” means more heat and “colder” means an increasing absence of heat. Same with the spectrum of light and absence of light (or dark).
Now, wrap your mind around two other spectrums, masculinity and femininity AND wrap your mind around the fact that these are two distinct spectrums! They are not binary opposites. The absence of masculinity is not femininity nor is the absence of femininity called masculinity.
Traditionally, in many cultures, these spectrums were associated with genitals but in our most modern era of awareness, that association has been broken so that any human, regardless of their genital makeup, is freer to explore any level of either or both spectrums.
Our understanding of gender and genital representation has evolved, and continues to evolve, as we continue to explore ourselves and get better clarity on who we are as individual beings.