Greek myth attempts to explain the origins of the world, and details the lives and adventures of a wide variety of gods, goddesses, heroes, heroines and mythological creatures. Greek mythology is explicitly embodied in a large collection of narratives, and implicitly in Greek representational arts, such as ancient vase-paintings and votive gifts. These accounts initially were disseminated in an oral-poetic tradition; today the Greek myths are known primarily from ancient Greek literature. The oldest known Greek literary sources, Homer's epic poems Iliad and Odyssey, focus on the Trojan War and its aftermath.