Canon R3 has a
24.0MP Full frame (36 x 24 mm ) sized Stacked CMOS sensor and features Digic X processor. On the other hand, Kodak Z950 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Canon R3's sensor provides 12MP more than Kodak Z950's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the R3 and Z950 sensor size comparison.
As seen above, Canon R3 has a 31.2x Larger sensor area than Kodak Z950. 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.