Both Fujifilm X-A10 and Sony HX100V have 16.0 MP resolution sensors but Fujifilm X-A10's sensor is APS-C (23.6 x 15.6 mm ) and Sony HX100V's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Fujifilm X-A10'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 HX100V.
Another difference between these two cameras is that Fujifilm X-A10's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the X-A10 and HX100V sensor size comparison.
As seen above, Fujifilm X-A10 has a 13.1x Larger sensor area than Sony HX100V. 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.