Oceanic basins can be described using various synonyms, reflecting the diverse nature of these vast, underwater regions. One term often used interchangeably with "oceanic basin" is "abyssal plain," which refers to the flat sea floor found at great depths beneath the ocean's surface. Another possible synonym, "seafloor," encompasses the entire surface beneath the water, including volcanic ridges, seamounts, and other features. "Mid-ocean ridge" specifically refers to the underwater mountain range that spans the ocean basins, formed by tectonic activity along the Earth's crust. Finally, "pelagic zone" describes the open ocean, including all waters not in contact with the seafloor, such as the surface and the deep water below.