The largest laptop screen size that the stand is guaranteed to be compatible with. For comparison: the smallest netbooks have a diagonal of 10 –
12 ", ultrabooks are somewhat larger — up to
14" ; among classic laptops, 13" corresponds to the most compact models,
15 —
16" — medium format,
17" — large, and
18.4" is actually the "ceiling" for modern laptops.
Usually, the maximum diagonal indicated in the characteristics corresponds to the size for which the stand was originally designed. However the vast majority of models are able to work with smaller laptops, but this point should be clarified separately. In addition, you should not buy a device that differs markedly in maximum diagonal from your laptop — for example, an 18" stand is unlikely to be convenient for a 12" netbook.
The size of the surface intended for the direct placement of a laptop. This parameter allows you to fairly accurately assess how the stand is suitable for your device — after all, even laptops with the same diagonal can vary slightly in length / width.
