There are many zones/layers of the ocean. They all vary based on the depth.
Sunlight zone: This zone gets the most sunlight, allowing plants to grow and life thrive to seals, sharks, sea lions, rays, and more. (0 feet- 656 feet)
Twilight zone: (656 feet- 3,280 feet) Only very dim light reaches this zone of the ocean. No plants grow here. Jellyfish, octopuses and squid thrive here.
Midnight zone: (3,280 feet- 13,123) This part of the ocean gets absolutely no sunlight at all. Some of the life that live here do not even have eyes. No plants grow here, and it is mostly inhabited with Viperfish, anglerfish, snipe eel, and tripod fish.
Abyss: (13,123- 19,685 feet) This is a zone deep down in the ocean. Most fish that live here do not even have backbones, such as sea spiders. Hagfish and blind shrimp inhabit this zone.
Hadal zone: (19,685- 36,197) Extreme depths are found mostly in deep water canyons and trenches. The water temperature here is very, very cold, just above freezing. Not much life exists here, but the sea cucumber does manage to live here.