Gender transition is the process of changing one's gender presentation or sex characteristics to accord with one's internal sense of gender identity – the idea of what it means to be a man or a woman, or to be non-binary or genderqueer. For transgender and transsexual people, this process commonly involves reassignment therapy (which may include hormone replacement therapy and sex reassignment surgery), with their gender identity being opposite that of their birth-assigned sex and gender. Transitioning might involve medical treatment, but it does not always involve it. Cross-dressers, drag queens, and drag kings tend not to transition, since their variant gender presentations are (usually) only adopted temporarily.