Panasonic GH5S has a
10.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine 10 processor. On the other hand, Nikon 1 AW1 has a
14.0MP 1-inch (13.2 x 8.8 mm ) sized CMOS sensor and features EXPEED 3A processor.
Another difference between these two cameras is that Panasonic GH5S'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 GH5S and 1 AW1 sensor size comparison.
As seen above, Panasonic GH5S has a 1.9x Larger sensor area than Nikon 1 AW1. 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.