Steps consist of
two parts- tread and riser. Tread is the flat surface that
makes up a step. It provides a smooth and safe transition
between steps and landings. Riser signifies to vertical
distance between each step. In simpler terms, tread is
horizontal part of a step and riser is its vertical portion.
Usually treads are preferred with front/longer edges
profiled to bullnose, pencil edge, half bullnose, etc.