How the shapes are fitted together. Interlocked offsets every other column or row and lets each shape overhang its cell by exactly the amount its geometry needs, so the tiles tessellate into one continuous surface — hexagons become a honeycomb, diamonds a lattice, parallelograms and chevrons a ribbon. Grid puts every tile squarely in its own cell instead. Rectangles, squares, octagons and crosses already tile edge to edge at zero gap and look the same either way; circles cannot tile at all.