Both Nikon P950 and Nikon S8200 have 16.0 MP resolution sensors but Nikon P950's sensor is (1/2. ) and Nikon S8200's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Nikon S8200'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 Nikon P950.
Below you can see the P950 and S8200 sensor size comparison.
As seen above, Nikon S8200 has a infx Larger sensor area than Nikon P950. 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.