The continental slope connects the continental shelf and the oceanic crust. It begins at the continental shelf break, or where the bottom sharply drops off into a seep slope. It usually begins at 430 feet (130 meters) depth and can be up to 20 km wide. The continental slope, which is still considered part of the continent, together with the continental shelf is called the continental margin.
Submarine canyons cut through many of the continental margins. Some of these have been carved by turbidity currents, which are bottom currents that carry lots of sediment.
Information provided by: http://www.onr.navy.mil