In more recent times, gender has been seen more broadly as a spectrum rather than something that is a binary male and female. Additionally, as gender is a construct that is created and upheld by our societies it may not express how we feel inside.
This can sometimes be difficult as our biological sex that we were assigned at birth may not align with who we feel we are as a person. As a result, people who feel this way may want to change their outward expression to better match how they feel inside.
People who feel this way can identify as transgender, not identifying with their assigned sex from birth and instead identifying with their gender identity, one’s own psychological sense of gender. Ways in which transgender people sometimes express this gender identity is by changing the way they look maybe through hair or makeup and what clothing they wear. Additionally, people who are transgender may look to surgical or medical treatment to further affirm their gender identity.