When the staircase is a project that need to be developed and prepared for the construction, there are more terms used. They all mean specific element of the staircase that need to be made and installed on the defined place so it would function best. Here are the terms and the meaning of them by definition:
Stringer: – The inclined sides of the stair carrying the steps.
Riser: – The vertical timber which closes the space between two steps.
Rise: – It is the vertical distance between the top of the one tread and the top of the tread immediately above it. Usually 175 mm.
Tread: – The board forming the top-surface upon which the foot is placed.
Go or Going: – The horizontal distance between the face of one riser and the face of the next. Usually 250 mm.  

Nosing: – The rounded edge of the tread projecting over the riser. Usually 20 mm.
Landing: – The floor at the beginning or the end of a stair flight and the intermediate floor between two flights.
Well or Well-hole: – The space in the centre of a staircase between the outer stringers of the flight.
Flight: – A complete set of stairs reaching from floor to floor or from floor to a landing.
Newel: – An upright post at each end of a flight of stairs to carry the handrails and sometimes also the stringers.
Handrail: – The support for the hands at the sides of the stair.

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