Volcanoes can be dangerous due to hazards like lava flows, ash falls, and pyroclastic flows. Lava is very hot liquid that can burn people. Ash falls make the air dirty and hard to breathe. Climate change from volcanoes can also make people ill by changing the climate too quickly. However, volcanoes are less dangerous than earthquakes, tsunamis, and hurricanes. The document also discusses different types of volcanic rocks like magma, igneous, andesite, ryolite, and basalt that are formed from lava, as well as the parts of a volcano.