<P> A ladder is a vertical or inclined set of rungs or steps . There are two types: rigid ladders that are self - supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such as those made of rope or aluminium, that may be hung from the top . The vertical members of a rigid ladder are called stringers or rails (US) or stiles (UK). Rigid ladders are usually portable, but some types are permanently fixed to a structure, building, or equipment . They are commonly made of metal, wood, or fiberglass, but they have been known to be made of tough plastic . </P> <P> Rigid ladders are available in many forms, such as: </P>

What is the steps of a ladder called