PlotRangeClipping is an option for graphics functions that specifies whether graphics objects should be clipped at the edge of the region defined by PlotRange, or should be allowed to extend to the actual edge of the image.
With PlotRangeClipping->True, any parts of objects that extend beyond the region defined by PlotRange will be clipped. With PlotRangeClipping->False they are not clipped until they reach the edge of the whole image.
With PlotRangeClipping->True, graphics objects are effectively clipped to the region defined by the rectangle from Scaled[{0, 0}] to Scaled[{1, 1}].