Young Black Haired Girl Outside Posing On Stairs In A Destroyed House

The step is composed of the tread and riser.
• Tread
The part of the stairway that is stepped on. It is constructed to the same specifications (thickness) as any other flooring. The tread "depth" is measured from the outer edge of the step to the vertical "riser" between steps. The "width" is measured from one side to the other.