Answer: Normal faults are caused by tensional stress that pulls the crust apart, causing the hanging wall to slide down relative to the footwall. When compression squeezes the crust into a smaller space, the hanging wall pushes up relative to the footwall.
The shear stress is generally defined as the force that allows the two plates to slide past one another. This type of stress acts parallel to the surface and it give rise to the formation of transform fault. Here the two blocks move in opposite direction by slide passing each other. For example, the San Andreas fault, that was formed due to the sharing of a transform fault between the Pacific plate and the North American plate.
In the given image, the fault is caused by the shear stress.
