It is important to note that being transgender does not necessarily imply anything about that person's sexual preference. Transgender individuals can be heterosexual, homosexual, asexual or anywhere else on the sexual preference spectrum.
Understanding what transgender means also necessitates understanding the difference between sex and gender. A person's sex is biological and physical, and includes the sex chromosomes, genitalia, reproductive structures and gonads. In contrast, gender references more sociological aspects of a person's identity, such as how people interact and feel about themselves is a term that is used to describe men and women who were born a certain sex, but feel their true gender is
the opposite. Some live completely - or part time - as the opposite sex. There are also some transgender people that get sex reassignment surgery, completely changing their gender.
The term transgender became widely used in the 1970s, although it is unknown just how long transgender people have existed. And at first referenced only those who wanted to live as another gender without having reassignment surgery. The term was expanded in the 1990s to
References: diversityguides.com/gay workplace/?p=98 www.merriam-webster.com/dictionary/transgender www.apa.org/pi/lgbc/trans www.transgenderlaw.org huffingtonpost.com transequality.org/federal_gov.html