This 8.5 x 11 notebook is a dual layout notebook.
It's designed with 5x5 graph paper on one side and lined paper (college ruled) on the other side.
Graph paper (coordinate paper, grid paper, squared paper or math paper) has many uses:
designing projectsdrawing maps for board/video/roleplay gamesplaying pen and pencil gamesdesigning floorplans, tiling or yard landscapingplanning embroidery, cross stitch or knittingThe inclusion of alternating pages with lined paper makes it easier to take notes to aid the illustrations, designs, maps etc.