Sex most commonly refers to:Biological sex, the trait of certain reproducing organisms producing either male or female gametes Legal sex or legal gender, a legal status Human sexual activity, a broad range of reproductive or erotic human practices Human sexuality, the way people express themselves in terms of, or experience, the above activities Sexual intercourse, the activity of using reproductive organs penetratively Animal sexual behaviour, the reproductive or erotic activities of non-human animals Copulation (zoology), in which a male introduces sperm to a female's body Sexual reproduction, reproduction that combines multiple gametes