The story: divine decisions threaten humanity; one survivor receives warning, constructs a vessel, preserves life, survives catastrophic water, and offers sacrifice. The Sumerian Ziusudra text, Akkadian Atra-ḫasīs, and Gilgamesh Tablet XI are related but not identical editions.
Why it matters: the tradition preserves arguments about population, divine responsibility, mortality, and the survival of civilization. Its relationship to Genesis is historically important, but the differences in theology, covenant, cause, and ending are equally important.