If someone looks androgynous, that means ey looks male and female in sufficiently equal doses for you not to be able to tell eir sex. Usually this is due to a lack of male and female secondary sexual characteristics rather than a significant amount of both, as the latter is known as genderfucking. For example, if you see someone with a beard and breasts, that's not really androgyny.
Androgyny doesn't necessarily have anything to do with a person's sex or gender, however. For example, a woman in a female body who's perfectly happy with eir gender and sex might just happen to look androgynous and be happy with that, too. Women, men and genderqueers can all be androgynes if they have the body for it and/or inclination for that kind of appearance.