Stairs are used to create a pedestrian route between different vertical levels by dividing the height between the levels into manageable steps. Very generally, the wprd stairs refers to a staircase, whereas the word step refers to the individual step that make up the staircase.
The maim components of the stairs are illustrated below:
Stairs, particilarly in domestic premises, may also include guarding to one, or bot sides, in the form of a bannister, that is, an assembly of uprights and a handrail. Stairs can be straight and can include a langding and turn, or can be curved. A continuous series of steps between landings is called a flight.
Curved stairs have tapered treads, and can be difficult to use. A helical stair has a void in the middle, where as a spiral stair has a column in the middle. Under some circumstances, stairs can have alternating treads, that is, the wide part of the tread is on alternating sides on consecutie treads. Stairs can be constructed using a wide variety of materials, including; timber, brick, stone, concrete, metal. glass and so on.