Now let's agree on the terms (something for the FAQ). I prefer the Wiki ones:
Cross-dressing (CD) is the act of wearing items of clothing and other accoutrements commonly associated with the opposite sex within a particular society.
Transvestism (TV) is the practice of dressing and acting in a style or manner traditionally associated with the opposite sex.
Transsexual (TS) people experience a gender identity that is inconsistent with, or not culturally associated with, their assigned sex, and desire to permanently transition to the gender with which they identify, usually seeking medical assistance (including hormone replacement therapy and other sex reassignment therapies) to help them align their body with their identified sex or gender.
Transgender (TG) people have a gender identity or gender expression that differs from their assigned sex.
Drag refers to the wearing of clothing of the opposite sex.
A drag queen is a person, usually male, who dresses in clothing of the opposite sex and often acts with exaggerated femininity and in feminine gender roles for the purpose of entertainment or fashion.
Drag kings are mostly female performance artists who dress in masculine drag and personify male gender stereotypes as part of an individual or group routine.
In other (mathematical) words:
CD = clothes
Example: a man wearing a dress, but he looks and feels like a man (see
http://hisblackdress.com/ )
CD is a subset of TV. TV = CD + (looking + acting)
Example: a man "impersonating" a woman (he dresses, looks and behaves like a woman).
Drag = exaggerated(TV) + show
TS is a subset of TG. TS = TV + self-identification + (hormone + surgery)
The difference between TV and TG is the self identity. TG feels that he/she belongs to another (politically correct term) sex.