Stone Steps and Stairs

Is there a difference between a step and a stair? After looking up both words in the dictionary, I’m still wondering because a step is defined as one of a series of structures consisting of a riser and tread, and a stair is considered the height of a single step in a flight of stairs.

Passing from one level to another, we take a step on a stair but not a stair on a step. So, I guess they’re not synonymous, exactly. I do know that if I build a set of stone steps, or a stone stairway, the steps and stairs had better have even rises and similar treads. Or, is that similar rises and even treads? While you’re pondering, have a look at two I recently built, along with their “before” photos.