Subduction is a geological process where one tectonic plate is forced beneath another plate. This occurs at convergent plate boundaries, where two tectonic plates collide. The subducting plate is usually dense oceanic crust, while the overriding plate can be either oceanic or continental crust. As the subducting plate moves into the Earth's mantle, it melts and can cause volcanic activity and earthquakes on the Earth's surface. Subduction zones are important features of plate tectonics and play a crucial role in the recycling of Earth's crust and the formation of mountain ranges and volcanic arcs. Research in this area focuses on understanding the processes and hazards associated with subduction zones.