A continental margin is the term given to the underwater boundaries between continents and ocean basins. These margins can be divided into two types: passive and active margins. Passive margins are the result of diverging plate boundaries, while active margins are associated with converging plate boundaries. Synonyms for this term can include continental shelf, abyssal plain, continental slope, and continental rise. The continental shelf is the shallowest part of the continental margin and can extend up to 200 meters into the ocean. The abyssal plain is the deepest part of the ocean floor and is often found at the foot of the continental slope. The continental slope is the steep portion of the continental margin that drops down into the abyssal plain. Finally, the continental rise is the gradual incline at the base of the continental slope.