A dome mountain is similar to a volcano in that they both form when molten rock, or magma, is pushed up from deep within the Earth and then cools and hardens. Both dome mountains and volcanoes are formed by the same process of magma pushing up and cooling, but the difference is that a dome mountain is formed when the magma cools and hardens without erupting, while a volcano is formed when the magma erupts and then cools and hardens.
