Gender expression refers to the way that a person uses appearance, mannerisms and other personal traits to communicate their gender. Gender expression can be any combination of masculine, feminine and androgynous traits.
Unlike sex characteristics which cannot be changed without medical intervention, gender expression usually refers to traits which can be changed voluntarily, at least to some degree. Traits which contribute to gender expression can include clothing and accessories, hairstyle, make-up, removal or growth of body hair, development of musculature through exercise, stance, and manner of walking, and manner of talking. The name, pronouns and titles you ask others to use in reference to you may also be considered a part of your gender expression.
A person of any gender identity can choose to express their personal experience of gender through any combination of traits, although some traits are stereotypically associated with certain identities. Some people, especially those who identify as agender and/or neutrois may wish to avoid all traits associated with gender, which can be difficult to do in a society based on the gender binary.
It is important to notice that one's gender expression does not always match their gender.