Figure 4.7 - Face borders in objects
To smooth the surface of any model, we have two shading options:
Shade Smooth
Shade Flat
By default, all models use Shade Flat, and in case you want to remove
visible borders between polygons, change it to Shade Smooth. The
option is available when you are in Object Mode. With an object
selected, right-click to open the Context menu (Figure 4.8).