Sony W830 has a
20.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Bionz processor. On the other hand, Kodak Z980 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Sony W830's sensor provides 8MP more than Kodak Z980'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 W830 and Z980 sensor size comparison.
Sony W830 and Kodak Z980 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.