This is similar to blockboard and to battenboard panels in that an outer skin encloses wooden battens. These are spaced, so for some uses what is lacking in strength is made up for by the lesser weight. The whole thing is a lot lighter, so easier to manage and lift, especially for bedheads. The downside is that the timbers within it don’t necessarily fall at the edges where you need them – but if you ask a joinery company to make up for you they will insert battens at the edges and set the whole within a frame which makes for a good solid structure, still of less weight than full blackboard, but as useable and as practical.