Short answers, pulled from the story.
Persephone is the daughter of Zeus and Demeter in ancient Greek mythology. She became queen of the underworld after her abduction by her uncle Hades and also served as the goddess of spring and vegetation. Her dual role as both a goddess of seasonal growth and ruler of the dead made her one of the most widely worshipped figures in the Greek world.
Persephone was bound to return to the underworld because she ate pomegranate seeds while there. Hades tricked her into eating them before Hermes arrived to take her back. Because she had tasted the food of the underworld, she was required to spend a portion of each year below; in earlier accounts one third of the year, in later versions by Ovid and Hyginus half the year.
The Eleusinian Mysteries were secret religious rites celebrated at the city of Eleusis that promised initiates a happy afterlife. Persephone and her mother Demeter were the central figures of these rites. Inscriptions refer to them as "the Goddesses," and the mysteries were tied to the autumn sowing, with Persephone's annual return from the underworld serving as a symbol of immortality.
The etymology is uncertain and may have Pre-Greek origins. Rudolf Wachter proposed that the first element reflects a term meaning sheaf of corn found in the Rig Veda and the Avesta, while the second element traces to a Proto-Indo-European root meaning to strike or beat, giving the combined sense of "she who beats the ears of corn." A popular folk reading derived the name from the Greek words meaning "to bring death."
At Epizephyrian Locris in Calabria, Persephone was worshipped as the protector of marriage and childbirth, a role normally held by Hera. Children of the city were dedicated to her and maidens brought their peplos to be blessed before marriage. Votive pinakes, terracotta tablets painted with scenes from her myth, were produced there during the fifth century BC; more than 5,000 of them survive in the National Museum of Magna Graecia in Reggio Calabria.
Persephone was one of the most important deities in Orphism. Gold leaves inscribed with verses for the dead were buried with believers, and Persephone appears frequently in them as a guide and shelter for souls, with the ideal afterlife destination described as her "sacred meadows and groves." Orphic cosmology also named her as the mother of the first Dionysus, sometimes called Zagreus, fathered by Zeus.