Let me try to clear this up. On this site we use the following definitions:
Transgender: an inclusive umbrella term which covers anyone who transcends their birth gender for any reason. This includes but is not limited to Androgynes, Crossdressers, Drag kings, Drag queens, Intersexuals, Transsexuals, and Transvestites.
In my case, I'm a crossdresser. This means I'm transgender. I choose to dress, so for me, being transgender is a choice.
Someone who is born transsexual, would usually not consider it a choice. But they are transgender, too.
And all the non-binary, genderfluid, genderless people, too. They're all transgender. We all are, heck, we have cisgender members, too. Hugs, Devlyn