Sex, Gender, and Sexual Orientation

Sexual orientation

An inherent or immutable enduring emotional, romantic or sexual attraction to other people. Note: an individual’s sexual orientation is independent of their gender identity.

Gender identity

One's innermost concept of self as male, female, a blend of both or neither – how individuals perceive themselves and what they call themselves. One's gender identity can be the same or different from their sex assigned at birth.

Gender expression

External appearance of one's gender identity, usually expressed through behavior, clothing, body characteristics or voice, and which may or may not conform to socially defined behaviors and characteristics typically associated with being either masculine or feminine.

Sex assigned at birth 

The sex, male, female or intersex, that a doctor or midwife uses to describe a child at birth based on their external anatomy.

--From the Human Rights Campaign