1. Convergent Plate Boundaries: This is the most common location for volcanoes. Here, two tectonic plates collide. One plate often slides beneath the other (subduction). As the sinking plate melts, magma rises to the surface, forming volcanoes. This is how the "Ring of Fire" around the Pacific Ocean was formed.

2. Divergent Plate Boundaries: These are areas where tectonic plates move apart. Magma rises from the Earth's mantle to fill the gap, creating new crust. This process can lead to volcanic activity, often forming mid-ocean ridges.

3. Hotspots: These are areas where plumes of hot magma rise from deep within the Earth's mantle. The magma can pierce through the overlying crust, creating volcanoes. These volcanoes can form in the middle of tectonic plates, not just at boundaries. The Hawaiian Islands are a prime example of a hotspot volcano chain.