Sex education can be described broadly as providing instruction and information about human sexuality and functioning. It can encompass a variety of topics including sexual anatomy and functioning, sexual activity and sexual intercourse, reproductive health, abstinence, birth control, the prevention of sexually transmitted infections, sexual violence, and the psychological and emotional aspects associated with close relationships and sexuality. Sex education can be formal, delivered according to a school board-approved curriculum in public or private educational settings or by health professionals; or informal, occurring through communication with family, friends, peer groups, religious or community organizations; through public health campaigns; or via the daily consumption of media messages. In this entry, research related to formal education is presented, followed by research related to informal education.