Here's why:

* Slide: A slide occurs when a block of material (rock, soil, etc.) moves downslope along a relatively flat surface, like a bedding plane or a fault. The movement is typically rapid and often triggered by events like heavy rainfall or seismic activity.

Here are some other mass movements that can occur:

* Creep: Slow, gradual movement of soil or rock downslope.

* Flow: Movement of soil, rock, or debris mixed with water, like a mudflow.

* Fall: The freefall of rock or debris from a cliff or steep slope.

Let me know if you have any other questions about mass movements!