Nikon S6500 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Sony W230 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the S6500 and W230 sensor size comparison.
Nikon S6500 and Sony W230 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Sony W230 has 32% larger pixel area (2.34µm2 vs 1.76µm2) compared to Nikon S6500, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.