Graphics, animated diagrams and video help viewers learn about volcanoes around the world and understand how volcanoes are formed - magma, tectonic plates, subduction, divergent boundary, eruptions, lava, volcanic cone; the parts of a volcano - magma chamber, caldera, craters, volcanic vents, fissures, ash clouds, active, dormant or extinct volcanoes; volcano types - cinder cones, composite (strato) volcanoes, shield volcanoes, and lava domes; and notable volcanic eruptions - the Ring of Fire, Mt. St. Helens, and Mt. Fuji.