This sets the number of sides in each of the pot's polygonal rings. It's a tradeoff between smoothness and performance: the more sides there are, the smoother the pot's surface is, but the longer it takes to render the pot. Too few sides gives the pot a jagged, faceted appearance; excessive values make the application sluggish. The default value of 100 is a reasonable starting point.
The Rings and Sides properties together determine the total number of facets, which is approximately Rings × Sides × 4. The exact number can be displayed via Mesh Information.
Don't use the Sides property to create polygonal pots, because the resulting facet count will be too low to resolve other mesh effects. To create polygonal pots, use Polygon Sides and the other polygon properties instead.