Abyssal plains are indeed some of the deepest areas of the ocean, but they are not the deepest parts overall. These vast, flat regions of the ocean floor are usually found between 3,000 and 6,000 meters below the surface and cover more than half of the Earth’s ocean floor.
However, the deepest parts of the ocean are the oceanic trenches, with the Mariana Trench holding the record at about 10,994 meters deep. So while abyssal plains are incredibly deep and significant to our ocean’s geography, they are not the absolute deepest locations in the oceans.