Being gender non-conforming means not conforming to gender stereotypes. For example, someone’s clothes, hairstyle, speech patterns, or hobbies might be considered more “feminine” or “masculine” than what’s stereotypically associated with their gender.
Gender non-conforming people may or may not be transgender. For example, some women who were raised and identify as women present themselves in ways that might be considered masculine, like by having short hair or wearing stereotypically masculine clothes. The term “tomboy” refers to girls who are gender non-conforming, which often means they play rough sports, hang out with boys, and dress in more masculine clothing.
Similarly, transgender people may be gender non-conforming, or they might conform to gender stereotypes for the gender they live and identify as.