@AverageSue :
Gender identity is a person's internal sense of their gender, which can be the same as or different from their assigned sex at birth. It's a deeply held feeling of being a woman, a man, both, neither, or somewhere in between.
Some examples of gender identities include:
Cisgender: A person's gender identity matches their assigned sex at birth
Transgender: A person's gender identity doesn't match their assigned sex at birth
Agender: A person doesn't identify with any gender
Non-binary: A person doesn't identify fully as a man or a woman
Genderqueer: A person identifies or expresses themselves beyond what is often linked to their assigned sex and gender
Gender identity is different from gender expression, which is how a person presents their gender through their clothing, physical appearance, behavior, and hairstyles. A person can also transition to bring their gender identity into alignment with their gender expression. Transitioning can include:
Telling friends, family, and coworkers about their gender identity
Changing their name and pronouns
Updating legal documents
Taking hormones
Having surgery