The boundary that separates the Earth's outer core from the mantle is known as the "Lithosphere-Asthenosphere boundary" or the "Moho" (Mohorovičić discontinuity). While the Moho primarily signifies the transition between the Earth's crust and mantle, the actual boundary between the mantle and the outer core is at a much deeper level in the Earth. This boundary is marked by a dramatic change in material properties, as the outer core is primarily molten metal, while the mantle is solid. Understanding this boundary is crucial for geology and our comprehension of Earth’s internal structure.