The continental shelf is the gently sloping region that extends from the shoreline to the continental slope. It is typically less than 200 meters deep and is formed by the accumulation of sediments.

The continental slope is the steep slope that connects the continental shelf to the abyssal plain. It is typically between 200 and 2,000 meters deep and is formed by the erosion of the continental shelf.

The abyssal plain is the flat, gently sloping region that covers most of the ocean floor. It is typically between 4,000 and 6,000 meters deep and is formed by the accumulation of sediments.

The mid-ocean ridge is the underwater mountain range that runs through the center of the ocean basins. It is formed by the spreading of the ocean floor and is the site of new ocean crust formation.

The rift valley is the deep, narrow valley that runs along the axis of the mid-ocean ridge. It is formed by the spreading of the ocean floor and is the site of new ocean crust formation.

Seafloor spreading is the process by which new ocean crust is formed at the mid-ocean ridge. It is caused by the convection of the Earth's mantle, which pushes apart the tectonic plates.

Subduction is the process by which old ocean crust is destroyed at the subduction zones. It occurs when one tectonic plate moves beneath another tectonic plate.

The Challenger Deep is the deepest part of the ocean. It is located in the Mariana Trench in the western Pacific Ocean and is approximately 11,000 meters deep.

A submarine canyon is an underwater canyon that cuts through the continental shelf and slope. It is typically formed by the erosion of the continental shelf and slope by turbidity currents.

A seamount is an underwater mountain that rises from the ocean floor but does not reach the surface. It is typically formed by volcanic activity.

A guyot is a flat-topped underwater mountain that is formed by the erosion of a seamount. It is typically found in the Pacific Ocean.

An abyssal hill is a small, hill-like feature that covers the abyssal plain. It is typically formed by volcanic activity.

A continental rise is a large, flat-topped underwater plateau that is formed by the accumulation of sediments. It is typically found at the base of the continental slope.

An oceanic trench is an underwater trench that is formed by the subduction of one tectonic plate beneath another. It is typically found in the western Pacific Ocean.