I have always wondered what pansexual was. When I googled what is was, it said that it is someone who not only likes men and women, even if they are transgender. That whole definition confuses me. Say you are a man who falls in love with a trans woman. If that person chooses to be a woman, could that man still be straight? And also, I am bisexual (I think at least) and I have been attracted to a trans woman before. Am I pansexual?
Pansexual generally includes non-binary gender identities as well; while bisexual generally means strictly the two binary sexes; according to what I have read and know at least.
Pansexuality is essentially crushing on anyone romantically, not based on looks or gender. They aren't limited based on gender or appearance.
The definition I agree with is "explicitly potentially attracted to people of any gender, including non-binary (ie, neither male nor female)". I don't think "bi" excludes trans women or trans men, since they are still women and men. Some people identify as elsewhere on the gender spectrum, and that's what pansexual tries to encompass. Other people will give different definitions, of course. That's the fun part. Lots of bisexual people are fine dating non-binaries. A straight guy dating a trans woman is still straight. A bisexual gay dating a trans woman is still bisexual. And it's not about "choosing" to be a woman.