It’s common for people to confuse sex, gender, and gender identity.  But they’re actually all different things.

• Sex is a label — male or female — that you’re assigned by a doctor at birth based on the genitals you’re born with and the chromosomes you have. It goes on your birth certificate.
• Gender is much more complex: It’s a social and legal status, and set of expectations from society, about behaviors, characteristics, and thoughts. Each culture has standards about the way that people should behave based on their gender. This is also generally male or female. But instead of being about body parts, it’s more about how you’re expected to act, because of your sex.
• Gender identity is how you feel inside and how you express your gender through clothing, behavior, and personal appearance. It’s a feeling that begins very early in life.