A volcanic arc is a chain of volcanoes formed above a subduction zone, where one tectonic plate moves under another and sinks into the mantle. This process generates magma, which rises to the surface, creating a series of volcanoes. Volcanic arcs are typically found along the edges of oceanic and continental plates. These arcs can be classified into two main types: island arcs and continental arcs. An example of an island arc is the Aleutian Islands in Alaska, while the Andes Mountains in South America represent a continental arc. Both types are characterized by explosive volcanic activity and diverse geological features.