Nikon 1 J5 has a
21.0MP 1' (13.2 x 8.8 mm ) sized BSI-CMOS sensor and features Expeed 5A processor. On the other hand, Fujifilm X-T20 has a
24.0MP APS-C (23.6 x 15.6 mm ) sized CMOS X-TRANS III sensor and features X-Processor Pro2 processor.
Another similarity between these two cameras is that both Fujifilm X-T20 and Nikon 1 J5 sensors lack anti-alias (Low-Pass) filters. 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 J5 and X-T20 sensor size comparison.
As seen above, Fujifilm X-T20 has a 3.2x Larger sensor area than Nikon 1 J5. 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.