1. Continental shelves: These are the gently sloping underwater extensions of the continents. They are relatively shallow, typically less than 200 meters deep, and rich in marine life.

2. Oceanic basins: These are the deep, vast areas of the ocean floor that lie beyond the continental shelves. They are characterized by their great depth, often exceeding 4,000 meters, and a diverse range of features like mid-ocean ridges, trenches, and abyssal plains.