What is the Purpose of Stair Landing?

Fig.4: Landing provided to allow stairway to change its direction

What are the cases in which stair landings are needed?

Fig.5: Doorway swing on landing of stairway

Fig.6: Doorway opens on toward the stairway

What the cases in which stair landing can be omitted?

What are the standard dimensions of stair landing?

Fig.7: Width of landing determined based on the stairway they serve