There are two main types of volcanoes - quiet and explosive. Quiet volcanoes erupt gently when the magma is hot and low in silica, allowing gases to bubble out slowly. The low-viscosity lava oozes from the vent and can flow long distances. Explosive volcanoes erupt violently when magma is high in silica, trapping gases under pressure until an explosive eruption occurs. Inside a volcano, magma rises from the magma chamber through a pipe and erupts at the vent, with the lava solidifying after flowing on the ground.