Both Nikon S9500 and Sony HX80 have 18.0 MP resolution sensors but Nikon S9500's sensor is 1/2.3-inch (6.16 x 4.62 mm ) and Sony HX80's sensor is (1/2. ).
Since Nikon S9500's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Sony HX80.
Below you can see the S9500 and HX80 sensor size comparison.
As seen above, Nikon S9500 has a infx Larger sensor area than Sony HX80. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.