Both Sony W230 and Olympus TG-6 have 12.0 MP resolution sensors but Sony W230's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Olympus TG-6's sensor is (1/2. ).
Since Sony W230's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Olympus TG-6.
Below you can see the W230 and TG-6 sensor size comparison.
As seen above, Sony W230 has a 0.0x Larger sensor area than Olympus TG-6. 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.