Seafloor spreading is a geological process that occurs at mid-ocean ridges, where tectonic plates pull apart. As these plates separate, magma from the Earth's mantle rises to fill the gap, creating new oceanic crust. This process helps explain how continents drift and how the ocean floor is constantly being renewed. As the new crust forms, it pushes older crust away from the ridge, causing the ocean floor to expand. This movement can lead to the formation of features like volcanoes and mountain ranges. Seafloor spreading is a key part of the theory of plate tectonics, which describes the dynamic nature of Earth's surface.