Kodak Astro Zoom AZ651 has a 21.0MP 1/2.3" (6.17 x 4.55 mm ) sized CMOS sensor . On the other hand, Sony a5100 has a 24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor.
Below you can see the Astro Zoom AZ651 and a5100 sensor size comparison.
As seen above, Sony a5100 has a 13.1x Larger sensor area than Kodak Astro Zoom AZ651. 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.