Risers are the vertical pieces at the back of each step that keeps your toe from going any further. Some stairs do not have risers. When they are used, they determine the height of the step.

Treads are the actual steps, where you put your foot as you climb the stairs. They determine the depth of the step.

Swell Step-Starter step-Double bull nose step
The swell step is the first step on the stairs. It can also be called the starter step. It is often larger than the rest of steps.

Balusters, also known as spindles, are the thin poles that go from the tread to the handrail.

Newel Posts
Newel posts serve the same function as the balusters except they are usually larger and found on the first and the last step or on thorns. They can also be found on landings. They come in different forms usually round or square.

The handrail is the rail that you place your hand on as you climb the stairs. The handrail can either be attached to the top of the balusters and newel posts or directly to a wall.

Small floor area where stair turns direction, it can be square or pie shaped.

String or Skirting
They are the wide panel molding on sides of the steps

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