Your sex – being male or female – is determined by your biological sex: what physical body parts, chromosomes, and hormones you have.
Your gender – being a boy or a girl, a man or a woman – refers to your feeling of being a man, a woman, both, neither, or somewhere else along the gender spectrum. Your gender may be the same as or different from the biological sex you were assigned at birth. It can be a fluid definition and can change over time.
Learn more about gender identity in our LGBTTQ+ section.