Sex refers to the biological and physiological characteristics that define humans as male or female. It involves differences in anatomy, reproductive systems, and secondary sexual characteristics, such as body hair and voice pitch.
Sex can also refer to sexual activity, which involves physical intimacy and can include a range of behaviors and practices. This activity can be part of a reproductive process or personal and emotional connection between individuals.
In discussions about human sexuality, it's important to distinguish between biological sex and gender, which encompasses a broader range of identities and roles beyond just biological factors.