A stairway, staircase, stairwell, flight of stairs, or simply stairs is a construction designed to bridge a large vertical distance by dividing it into smaller vertical distances, called steps. Stairs may be straight, round, or may consist of two or more straight pieces connected at angles. Special types of stairs include escalators and ladders. Some alternatives to stairs are elevators, stairlifts and inclined moving walkways as well as stationary inclined sidewalks.