Stair riser

A stair riser is the near-vertical element in a set of stairs, forming the space between one step and the next. It is sometimes slightly inclined from the vertical so that its top is closer than its base to the person climbing the stairs. The horizontal edge of the stair is called the nosing, whereas the surface on which a person's whole foot makes contact is called the tread.

Stair riser

A stair riser is the near-vertical element in a set of stairs, forming the space between one step and the next. It is sometimes slightly inclined from the vertical so that its top is closer than its base to the person climbing the stairs. The horizontal edge of the stair is called the nosing, whereas the surface on which a person's whole foot makes contact is called the tread.