Here's why:

* Faults are fractures in the Earth's crust where rocks have moved past each other. This movement can be in different directions:

* Strike-slip faults: The rocks move horizontally past each other, like a sliding door.

* Dip-slip faults: The rocks move vertically past each other.

* Oblique-slip faults: The rocks move both horizontally and vertically.

Example:

Imagine two blocks of rock on either side of a crack. If the block on the left moves to the right, and the block on the right moves to the left, this would be a strike-slip fault.

Let me know if you have any more questions about faults!