It's kinda like bisexual in that it includes men and women, except it also includes transgender, agender, genderqueer, etc. We're basically attracted to people regardless of biological sex, people of any gender or neither gender, if they identify that way. It doesn't matter to us.
Agender means you don't identify as any gender, and genderqueer basically means, I believe, that you do not subscribe to typical gender norms (you identify as both, neither, or a combo of genders). I may not be one hundred percent correct though, I'm neither agender or genderqueer so I can't give you first hand experience, but I think that's the general idea.
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