The Pinch Deformer can be used to sculpt Shapes.
Active - enable/ disable the Deformer. This is useful when initially placing the Falloffs for Bind Area and Pinch Point.
Bind Area - the area where the Pinch is active. By default, when you create a Pinch Deformer a Falloff called Pinch Binder is added and connected to this attribute. Any shape points falling within this Falloff will be affected with any outside being ignored.
Pinch Point - by default, a Null called Pinch Mover is created and connected to this attribute when creating a Pinch Deformer. This Null can then be repositioned to 'pinch' the Shape it is deforming.