Moving stairway and Stairs

Moving stairway noun - A stairway whose steps move continuously on a circulating belt.

Stairs and moving stairway are semantically related. In some cases you can use "Stairs" instead a noun phrase "Moving stairway".

Stairs noun - A flight of stairs or a flight of steps.

Moving stairway and stairs are semantically related. You can use "Moving stairway" instead a noun "Stairs".