Sex refers to the biological, anatomical, physiological and chromosomal difference between females and males present at birth such as the presence of a vagina or penis, menstruation or sperm production, difference in genetic make-up etc. Sex is also used to describe physical sexual acts that include, but are not limited to, vaginal, anal, oral intercourse, masturbation and kissing among other acts.
Sexuality is the erotic aspect of the human experience throughout life, experienced in fantasies, desires, beliefs and behaviors. Aside from its reproductive aspects, sexuality encompasses gender identity, gender norms and roles and sexual orientations and identities. Also, sexuality is influenced by the interaction of social, biological, economic and political dimensions, particularly as constructed under patriarchal and heteronormative systems of power that run society.
Sexual orientation, on the other hand, describes and categorizes sexual attraction towards the other, mainly as whether attraction is towards people of the same sex/gender, a different sex/gender, or to more than one gender. Sexual orientation can be seen as categories (heterosexual, homosexual, bisexual) or as a fluid description of sexual desire and attraction.