Convergent boundaries - this is where two plates move towards one another. The oceanic crust sinks beneath the continental crust at a subduction zone - a point where one crustal plate is forced beneath another. As the oceanic crust sinks into the mantle, it creates magma, which rises to form an explosive volcano.
Volcanoes affect different places in different ways. They cause more damage in poorer countries, where there are fewer resources to predict and prepare for them.
Mount Aso in Japan is one of the world's most active volcanoes