An active volcano is a volcano that has erupted recently and is likely to erupt again in the future. These eruptions can vary in intensity, producing lava flows, ash clouds, and pyroclastic flows. Scientists monitor active volcanoes to predict eruptions and ensure the safety of nearby communities. Active volcanoes are often found along tectonic plate boundaries, where the Earth's crust is unstable. Famous examples include Mount St. Helens in the United States and Kilauea in Hawaii. Understanding active volcanoes helps researchers study geological processes and mitigate risks associated with volcanic activity.