"Am I Trans?"Edit
A person can reside under the trans umbrella due to an intellectual awareness that one's sense of self is "different" from one's physical sex - this is referred to as a "gender identity" issue, or from an emotional need to express oneself sometimes as the opposite gender (or perhaps as a blended gender, as in conscious androgyny) -- referred to as one of "gender expression." Only you can determine for yourself if you are trans and where in that continuum you will be most comfortable, but it helps to understand some of the general definitions. In doing so, don't allow yourself to be limited by or defined by the label -- they're only tools to help you sort things and find where you fit.
There are sometimes conflicts with the terms transvestite and crossdresser. Both are about people who feel a need to (at least periodically) dress in the clothing worn by the opposite gender. By clinical definition, a transvestite is motivated by purely sexual desire, a fetish mostly about the clothing itself, which is why it is considered a paraphilia. Meanwhile, a crossdresser may have some sexual element or may not, but it is not their primary reason for crossdressing -- dressing as the opposite gender fulfills a deep psychological need, and is often described as comforting, or carry a feeling of appropriateness.
[Personally, I've come to think the sexual fetish / paraphilia assumptions are all a bunch of poo. Yes, there are some transvestites whose drive is caused by something other than gender dysphoria, and I'm not knowledgeable enough on that to comment on them -- but there are also some for whom this is a submerged form of GID that has been buried so much that it only expresses itself during sexual play. In the latter cases, I don't think we honestly understand what "fetish" is, and I strongly believe that our "fetishes" say something very intrinsic, subconscious and personal about us, even if we don't grok the sometimes-strange surface meanings. Additionally, I suspect the difference between transgender people with strong sexual elements and the average woman who likes to dress up and feel sexy on occasion can be accounted for at least in part by elevated testosterone levels. -- Mercedes]
As mentioned, crossdressers can come from different perspectives. Some need to express a different gender part-time, and would never want to transition physically (gender expression) -- in fact, many of these also find that they need to express their birth gender at times, as well. Others have strong transsexual leanings but feel held back by life circumstances (spouse, children, job, finances, responsibilities), and choose to express the gender that feels truer to them behind closed doors, when circumstances permit (gender identity).
Androgynous / "Genderf---": Androgyny is not always conscious, and many people in this range would not consider themselves "transgendered." Some people choose to play with gender in real life, for a wide number of reasons. For some, it can be to express both a feminine and masculine side simultaneously. Others enjoy the "genderplay" process by which they can challenge other peoples' beliefs and preconceptions. A few are even just out for shock value, while others may consider themselves bigendered.
Drag performance is genderplay taken to the extreme, and very much about the art of the performance. Most approach drag as an issue of gender expression, and are primarily entertainers at heart. There are also some who are transgendered at heart, and have found the drag community a comfortable environment to express that.
Transsexual: A transexual is the proverbial "woman in a man's body" (or vice versa). She (in the case of a male-to-female, or MTF) is more female than male in her mind, identifies with women, empathizes with women, and can be extremely uncomfortable with her male body. She will feel like she is always being forced to "act" a certain way to make other people happy, and not at all allowed to express who she truly is. She will also have become extremely tired of putting on this performance, and having to live a double-life as a crossdresser -- tired enough that she feels the need to even risk losing loved ones, her job and everything else in order to change her gender.
There are also a number of variations within the transsexual community. There is a growing number who physically transition from female to male (FTM). There are also a number of differences based on the surgical status: pre-operative (or pre-op, intending to have surgery but not having had it as yet), post-op, mid-op (this is especially common for FTM transsexuals, for whom there are several operations, usually necessarily spaced apart), semi-op (those who choose some surgical intervention and then choose to stop at a certain point) and non-op (either not able to have surgery -- i.e. for health or financial reasons -- or choosing to not have surgery). There are a number of reasons that a transsexual might choose not to have surgical intervention. In the MTF path, for example, there are a number of surgical options available, and not all are pleased with what they've seen or heard (which is not to say that MTFs tend to be dissatisfied -- many are in fact quite happy with the results). There are also some who come to identify as "transsexual" moreso than as "female" or "male," and take a certain amount of pride in being differently-gendered.
[The term "shemale" (et al.) used to describe pre-op or non-op transsexuals derives from porn, and is often not considered a respectful term outside of that medium.]
Keep in Mind That:
1) Who you are does not dictate who you love. Trans is not a sexual orientation. If you are a male-to-female transperson of any type, for example, that does not automatically mean that you are gay and desire a man. The two are entirely independent facets, and a transperson can be attracted to men, or women, or both. Sometimes, orientation can seem a little obscured, such as the case of a transwoman who is more physically attracted to women but more emotionally and psychologically attracted to men. This is something which is entirely up to the transperson to discover, and transition will not define it. Hormones may sometimes sway it in a subtle manner, but not always.
2) Gender is more broadly defined than it had been in previous decades, but it can still be too narrow for comfort, for trans people. We may never completely fit a societal definition of any one single gender. You cannot stake all your hopes on a concept of "completion," or you may be disappointed. The truth is, genetic women often have masculine traits, and genetic men can often have feminine ones. Do not be afraid to retain those traits that are a part of you -- you do not have to sacrifice them to become a perfect specimen. Transition is about becoming who you are, and taking off the mask... it is not about trading one mask for another.
3) Trans is most often not a fetish unto itself (see discussion above about the term "transvestite" for the one grey area). A fetish by current social thinking is a trigger (visual, sensual or psychological) that functions like fantasy. With fetish, you enjoy the idea for a time, and then return to a more conventional way of life with which you are comfortable. For transsexuals, it is not about a temporary excitement -- it is a case of truly being the opposite sex in your mind, and having to hide it during the day-to-day. For the transsexual, the drive does not go away after some play or dress-up experience -- in the morning, an MTF is still emotionally female and an FTM is still emotionally male. For crossdressers, the motivations can vary, but for many, there is a psychological sense of relief from being able to express oneself by dressing and presenting.