Christmas cards and picture books usually show a stable as a small building in a meadow or field and the manger as a box like a bassinet with the infant Jesus lying in it.
But that is completely wrong.
The manger was a feeding trough, big enough for Mary to lie in while giving birth.
The stable of an inn was usually the rear part of the ground floor, behind the kitchen and the room where guests signed in and had their meals. The bedrooms were all upstairs.
That stable would have been full of steeds belonging to other guests at the inn, and perhaps the inn owners. And it probably didn’t smell very pleasant.