* Plate boundaries are zones of intense geological activity: The movement of tectonic plates causes friction, pressure, and the melting of rock, all of which contribute to earthquakes and volcanic eruptions.

* Most earthquakes and volcanoes occur at plate boundaries: About 90% of earthquakes and 80% of active volcanoes are found at plate boundaries.

* There are exceptions:

* Intraplate earthquakes: Some earthquakes occur within tectonic plates, often due to stresses caused by plate movement. These are less common but can be significant.

* Hotspots: These are areas of volcanic activity that are not directly associated with plate boundaries. They are thought to be caused by plumes of hot rock rising from deep within the Earth's mantle.

In summary: While the majority of earthquakes and volcanoes occur at plate boundaries, there are some exceptions to this rule.