Figure 4.6 - Different levels of subdivision
With the Quality value, you can control the accuracy of how your
modifier will place the vertices concerning the original object. Higher
values will result in more precision locations but will add more
computational load to the model.
4.2.1 Controlling surface smoothing
Even after using the Subdivision Surface modifier in a model, you might
still see a few faces showing up. The modifier helps to create a smooth
surface for the model, but won't remove visible borders from the faces it
creates (Figure 4.7).