Canon A3300 IS has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features DIGIC 4 with iSAPS technology processor. On the other hand, Canon G9 X II has a
20.0MP 1″ (13.2 x 8.8 mm ) sized BSI-CMOS sensor and features DIGIC 7 processor.
Below you can see the A3300 IS and G9 X II sensor size comparison.
As seen above, Canon G9 X II has a 4.1x Larger sensor area than Canon A3300 IS. 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.