The document defines key terms related to volcanoes such as magma chamber, central vent, conduit, and crater. It then describes the three major types of volcanoes: cinder cone volcanoes, shield volcanoes, and composite volcanoes. Cinder cone volcanoes are small and steep sided, building from lava fragments. Shield volcanoes form large, gentle sloped mountains from slowly flowing lava. Composite volcanoes have steep, layered sides and can erupt explosively without warning.