A Single wallboard

Is made from two Single-Wall Flat Pads and a flute that has been glued together. It is manufactured of various kinds and grades of paperboard. It is also available in E-flute, B-flute, C-flute and F-flute form. This popular and versatile 3-ply construction is converted into a wide variety of containers and packaging components

 A Double wallboard

Is made from three Single-Wall Flat Pads and two flutes that have been glued together. It is manufactured of various kinds and grades of paperboard. A Double wallboard is designed for packing heavy items where high flexibility and protection is required.

 A Triple wallboard

Is basically made by adding Single-Wall layer to a Double-Wall board.
Triple corrugated is usually manufactured by two layers of C Flute and one layer of B Flute. It is highly strange and very good as storage box.