Are 'steps' and 'stairs' the same thing? | Merriam-Webster
When they're outside, they're more often called 'steps' than they are called 'stairs.'. Steps lexically has the emphasis on the single structure that is the riser and the tread. The singular form step is the usual way to refer to the structure (evidence of "the bottom/top step" abounds while evidence of "the bottom/top stair" is scant, especially in American English).