What causes earthquakes to occur along plate boundaries?

Earthquakes occur along plate boundaries due to the movement of tectonic plates. Plates can collide, slide past, or move away from each other, causing stress to build up in the Earth’s crust. When the stress exceeds the strength of the rocks, it is released as seismic energy, resulting in an earthquake. Fault lines, such as the San Andreas Fault, are common sites for this activity.