Volcanoes made from the accumulated heat of some where under Earth’s crust that creates Magma and gas in that area and incurred pressure and highest heat so it will erupting continued an explosion.
When magma under Earth’s crust breaks through to the surface, it creates a volcano. Mostly the volcanoes will be incurred where the crust is the weakest or we call the Ring of Fire such as in Indonesia , Philippines , Japan , South Korea etc.