An active volcano is a volcano that has erupted recently or is showing signs of potential eruption in the near future. Active volcanoes are typically monitored by scientists to assess the risk of an eruption and to develop plans to mitigate the risks.

Active volcanoes can be found in many parts of the world, but they are most concentrated in the Pacific Ring of Fire, a region around the Pacific Ocean that is home to about 75% of the world's active volcanoes. Some of the most well-known active volcanoes include Mount Vesuvius in Italy, Mount Etna in Sicily, and Kilauea in Hawaii.

Active volcanoes can pose a significant risk to human populations, as they can erupt without warning and cause widespread damage and loss of life. Volcanic eruptions can produce lava flows, ash clouds, and pyroclastic flows, all of which can be deadly.

In addition to the immediate risks associated with volcanic eruptions, active volcanoes can also have a long-term impact on the environment and human populations. Volcanic ash can block sunlight and cause cooling, and lava flows can destroy forests and infrastructure. Active volcanoes can also release harmful gases and chemicals into the atmosphere, which can contribute to air pollution and climate change.

Despite the risks, active volcanoes also provide important benefits. They can be a source of geothermal energy, and the ash and lava from volcanic eruptions can help to fertilize the soil. In addition, active volcanoes can be a source of tourism and recreation.