A: There are so many options with cellular shades, it's sometimes hard to tell them apart!
Most cellular shades come in single, double, or triple cell layers. Obviously, a single layer of cells is usually thinner than double or triple cell layers, but this isn't always the case. Since cellular shades come in lots of cell sizes (like I said, there are LOTS of options with cellular shades) a single layer of large cells can sometimes be as thick as a double layer of small cells!
Mostly, though, cell counts (referring to cell layers, of course) give cellular shades their trademark insulating qualities. Triple cell layers give you more insulation against heat and noise than double layers, and double give more than single. It's actually pretty easy, but you'll need to keep in mind the depth of your window, too. Triple layer cellular shades are great, but they can get pretty thick!