This is found under the flooring of a house. This gives a solid, flat, smooth structure for the flooring to be laid on top of because there are gaps in between the floor joist. The plywood subflooring also helps keep the layer level smooth and well-insulated.
Structural Wall Sheathing
This is located in the walls of a structure. Their purpose is to provide a surface for materials to be attached to as well as some insulation. It also is meant to keep water and wind out as well as be a radiant barrier. It's applied directly to the wall framing .
Building Façade(Wood Siding)
Building siding, as it sounds, involves the side of the building, specifically the inside. It goes on the inside of a smaller room and on the wall studs to become a type of wall sheathing. It covers and fills the gapes of the studs and allows additional walls to be built off of it.