The "Feywild" is a relatively recent name for the spiritual gods-realm that was once the sole domain of Parvati, goddess of life. Before the godswar, the devoted of Parvati could, with her favor, visit a realm of abundant growing things, animals living peacefully with one another, where nothing was born and nothing died and all things flourished.
Since the godswar, however, and the death of Mahadeva and Parvati's assumption of the roles of birth and death, her former realm of peaceful life has grown wild and strange. Predatory creatures now act out their cycles of life and death, and the old paths are not as safe as they once were. The realm is full of strange "fey" creatures, granting the place its new moniker among those who have dared to visit.
The goddess still occasionally walks this realm, in her more stable moments, but her attention is split and she has formally ceded day-to-day control of it to Aranyani, eldest and most powerful of the Elves who turned from Surya's service to join Parvati at the end of the war. Aranyani and her followers, or at least those who did not choose mortality as wood-elves, made their exodus here where the centuries of constant life has made them almost as strange, dangerous, and mercurial as the plants and animals.
The Feywild is a place of secrets, power, and danger but it remains a popular destination for spiritual travelers seeking answers to the mysteries of life.