Simplify the following text for a Grade 3 native English-speaking person.
Original: A fault scarp is the topographic expression of faulting attributed to the displacement of the land surface by movement along faults . They are exhibited either by differential movement and subsequent erosion along an old inactive geologic fault ( a sort of old rupture ) , or by a movement on a recent active fault .
Simplified: A fault scarp is a steep cliff made by movement along one side of a fault .