Balusters - Vertical posts that support the handrail system.  Often called spindles.

Balustrade - Refers to the collection of newels, balusters and handrail on a staircase.

Fittings - Specifically designed stair parts that provide a smooth transition during handrail height changes or handrail directional changes.  Examples:  volutes, turnouts, starting easings and goosenecks.

Gooseneck - A handrail fitting used at a landing or balcony to complete a smooth transition between varying heights.

Handrail - The horizontal member or balustrade system that sits on top of the balusters and is supported by the newel posts.

Landing Newel - A newal post positioned at a landing or balcony.

Landing Tread - A structural moulding, used on all landings and balconies, to create a transition between the stair and the finished floor, and also as a level surface to attach balusters.  Standard width:  3-1/2" or 5-1/2" and overhangs the balcony 1 " or 1-1/4", allowing cover or trim to be ran underneath.

Level Quarter Turn - A level handrail fitting that turns 90 degrees.

Newel Posts (Box, Volute, Standard) - Larger than a baluster.  Found at the top and bottom of the staircase and every 8' on balconies.

Over-the-Post - A balustrade system that utilizes fittings to smoothly transition over newel posts forming a fluid line of continuous handrail.

Post-to-Post - A balustrade system that utilizes fittings to smoothly transition over newel posts forming a fluid line of continuous handrail.

Rake - The staircase angle or slope.

Riser - The vertical face of the step.

Rosettes - Decorative pieces that end a handrail system at the wall line.

Stringers - Structure that supports the risers, treads and balustrades.

Tread - The step or part of the stair one walks on.

Tread Brackets - A decorative moulding that is fastened to the outside of the stringer.

Volute - A handrail fitting that is typically used on a Pin Top starting newel and curves away from the stair in a circular manner.