Dioecious is the botanical term for separate male and female plants, which is the whole reason regular seed exists, but some industrial hemp varieties have been bred monoecious so every plant carries both flowers and self seeds. Those monoecious lines are useful for grain farmers and useless for anyone wanting to select a male. The distinction, and why monoecious pollen drifting into a garden is a particular nuisance, is explained at https://breederregularseeds.com in a short primer. Worth knowing if you live near hemp fields.