People whose gender identity or expression does not conform to the sex they were assigned at birth are transgender. While individuals may be assigned to a sex at birth based on how they present biologically, their sense of their gender may differ. A trans man is a man who was identified as female at birth, and a trans woman is a woman who was identified as male. (Transsexual is an older term that referred to trans individuals who sought or undertook intervention to change their bodies.)| Psychology Today
All humans are born with biological characteristics of sex, either male, female, or intersex. Gender, however, is a social construct and generally based on the norms, behaviors, and societal roles expected of individuals based primarily on their sex. Gender identity describes a person’s self-perceived gender, which could be male, female, or otherwise.| Psychology Today