The three main types of plate boundaries are:
- Convergent boundaries: where two tectonic plates move toward each other, which can cause mountains to form or lead to one plate sliding under another.
- Divergent boundaries: where plates move apart from each other. This usually happens at mid-ocean ridges and can create new ocean floor.
- Transform boundaries: where plates slide past one another horizontally. This can cause earthquakes along fault lines, like the San Andreas Fault in California.