A volcanic eruption is a natural phenomenon that occurs when molten rock, ash, and gases are released from a volcano. This happens due to the buildup of pressure beneath the Earth's surface. Magma, which is molten rock, rises to the surface through vents and fissures. When the pressure becomes too great, it results in an eruption. The eruption can have devastating effects, including lahars, ashfall, and pyroclastic flows. Understanding the process helps us to mitigate the risks associated with volcanic activity.