Volcanic structures are formations created by volcanic activity, primarily involving the eruption of magma from beneath the Earth's surface. These structures can include volcanoes, which are mountains formed by the accumulation of lava and ash, and calderas, large depressions that occur when a volcano erupts and collapses. Other types include lava plateaus, formed by extensive lava flows, and fissures, which are cracks in the Earth's crust where lava escapes. Different volcanic structures can vary in shape and size, influenced by the type of eruption and the composition of the magma. For example, shield volcanoes have gentle slopes due to low-viscosity lava, while stratovolcanoes are steeper and formed from alternating layers of lava and ash. Understanding these structures helps scientists predict volcanic activity and assess potential hazards.