The deep ocean refers to the deeper layers of the world's oceans, which are located at depths greater than 100 meters. This area is often referred to as the abyssal zone and extends down to about 6,000 meters (or around 20,000 feet) in some areas. The deep ocean is a vast and largely unexplored region of our planet, with unique ecosystems, extreme conditions, and fascinating creatures that have adapted to survive in this harsh environment.