What is the beam above the rest platform of this staircase section diagram staircase beams

Red circle 1, generally is the floor frame beam. There are two design ideas, method 1 is the floor frame beam elevation remains unchanged, the stairwell window and floor windows on the outside, is the same height, like the figure you give. Method 2 is to set up beams in the staircase platform, like the following figure 2 circle outside the beams, and the floor does not set up beams, windows in the upper red circle 1, at this time the staircase window and the floor of the window on the outside look, is staggered.

Red circle 2, generally the flap of the platform, not a beam

See below