Smooth
The Smooth brush is one of the most important Sculpting brushes. Often, non-homogenous artefacting results when sculpting (e.g., when using a very fine stencil) due to limited subdivision, as can be seen at the left of the image below:
The Smooth brush – with a low Strength value – is ideal for, relaxing’ the mesh and removing such artefacting.
Tip:Due to its importance, the smoothing function can be enabled for any brush by pressing the Shift key during use.
An overview of all available brushes can be found here: Brushes.