Abyssal Plain: A very wide and flat section of the deep ocean floor made of thick sediment
Continental Rise: The area of the ocean at the bottom of the continental slope; vast underwater hill made from tons of accumulated sediment
Continental Shelf: The underwater edge of a continent
Continental Slope: The steep cliff-like drop from the continental edge to the ocean floor
Ocean Trench:A large indentation in the floor, similar to a canyon on land. Ocean Trench are very deep.