Gender identity, just like sexual orientation, is based in the brain. This means that even though you might have female body parts—a vulva, vagina and ovaries—you might not feel like a girl. The same goes for a guy who has a penis and testicles, but doesn’t feel like his male body parts match the feelings he has inside.

People who believe their gender identity—the feelings they have inside—are different from their body parts may identify themselves as transgender or genderqueer.