The term "transgender" seems to be the media's preferred term these days for anyone who does not fit the conventional gender roles, and the media applies this term to many diverse individuals. But, as a professional writer and editor, the precision of language is important to me. And "transgender" is really an imprecise, meaningless term. It essentially means anyone who transcends gender. That could be a guy who gets a thrill wearing a dress, or a drag queen who dresses up to entertain, or an individual who genuinely identifies as the opposite sex.
I'm old enough to remember when "transvestite" and "transsexual" were commonly used terms in this area, though both terms seem to be considered derogatory and politically incorrect these days. That is unfortunate, because those terms are much more precise, accurate, and descriptive than the bland, can-mean-anything "transgender." And neither is derogatory, both are simply descriptive. A transvestite is simply an individual who wears clothes of the opposite gender. "Vest" refers to clothes. Nothing bad about that. It means the same thing as a crossdresser, though some people nitpick about that. A transsexual is an individual who (through hormones and/or surgery) has become, is in the process of becoming, or wishes to become the opposite sex.
Chelsea Maning is a transsexual. I am a transvestite/crossdresser. There have been times when I thought I was a transsexual, but those thoughts always go away. That's how I know they are not real.
I prefer honesty, precision, and directness in language, regardless of political correctness. It aids in understanding each other clearly. I always say that if people would just learn to communicate more clearly, 90 percent of the world's problems would immediately vanish.