Trying to explain anything as complex as gender in a short article is a daunting task. It is so much more complex than we as Americans ever acknowledge. Please understand that the following is based on personal research, my individual experience as a trans-man and as someone who has been widely involved in the transgender community for many years.
What does "transgender" mean?
Transgender is an umbrella term and can include many whose personal experiences with gender tends to cross traditional male/female boundaries and whose gendered appearance or presentation does not conform to customary gender and/or social role standards, based on their assigned birth anatomy. Consider though, that defining gender is highly subjective and can vary a great deal from one person to the next. There is no "one way" to be transgender.
Transsexual refers to persons who make permanent changes to their body, often including hormone therapy and/or surgery to help make the way they look on the outside better match how they feel on the inside. For some people, gender is a bit more complicated and they may not feel as compelled to make permanent changes, they just occasionally explore their gender.
Gender non-conforming, genderqueer, gender variant, non-binary, gender-fluid and gender-hybrid are just a few of the terms which describe those with androgynous, fluid or mixed gender presentations and/or identity.
Cross-dressers (transvestites) and female/male impersonators (drag queens, drag kings) may have a partial cross-gender identity, which is presented or validated on an occasional basis. Cross-dressers tend to be straight men who typically explore their gender in private. Male and female impersonators tend to be gay or lesbian identified and more often present in social or public settings.
Intersex (intersex has come into preferred usage, since the word hermaphrodite is considered to be misleading and stigmatizing) is a general term used for a variety of conditions in which a person is born with a reproductive or sexual anatomy that doesn't fit the typical definitions of female or male.
Cisgender is a term for an internal sense of gender and physical body that match or "align" (non-transgender people).
Sex vs. Gender
Sex is between your legs, gender is between your ears. Sex encompasses your physical and biological organs, secondary sex characteristics and body functions. Gender reflects who you feel you are, your sense of being male or female, masculine or feminine. There is no single, universally accepted definition or characteristic that absolutely differentiates male from female.
Gender Identity, Gender Expression and Sexual Orientation
Your gender identity is the core definition of your person and sense of self, who you are, your sense of being a man, a woman or possibly both.
Gender expression is how you, or how others perceive your manifestation of gender; typically masculine or feminine and it may be culturally directed or socially defined (dress, hairstyle, behavior, roles). Gender impacts every relationship and every social interaction.
Sexual orientation defines the gender and/or sexual anatomy that you are sexually and emotionally attracted to. Everyone has a gender, a gender expression and a sexual orientation. Transgender people may be straight, gay, bi, poly, etc. in their sexual orientation however, many tend to be bisexual (attracted to both men/males and women/females) and/or pansexual, attracted to all variations on the sex/gender spectrum).
Who Are Transgender People?
Transgender people are highly diverse and come from all ethnic groups and races, locals, socio-economic backgrounds and have existed throughout time. The "transgender spectrum" is a natural variation of the human experience and approximately two percent of the general population crosses or blurs gender boundaries.
There are currently about 700,000 transsexual people in United States or about three tenths of a percent of the adult population. Some people may no longer consider themselves to be transgender or transsexual after completing surgery and some may never identify as LGBT their whole lives. Some may seek to confirm society's strict gender binary (only male or female), while others may reject or oppose it. Occasionally, some may choose to retain family and relationships rather than transition (undergoing body changes and living openly as other gender) out of the fear of loss.
All transgender people deserve respect and tolerance. "Sex change" and "Tranny" are usually seen as derogatory terms. Please understand that it is inappropriate to ask a known transgender person about their genital/surgical status and it is also not okay to "out" a transperson to another transperson or to others. Many transgender people still face tremendous societal discrimination, injustice, and "criminalized gender," and yet most transgender people report a sense of happiness and fulfillment after transition and often become more productive employees and citizens.
Tremendous inroads have been made politically and legally toward finding some basic equality and rights as a community, but there is still a long way to go and many challenges. Finally, it is important to realize that if someone else's gender presentation bothers you, please take a moment and think about why. Recognize that it is your problem, not theirs. Like everyone else, transgender people are just trying to live comfortable and authentic lives.