Samsung ST80 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Leica SL2-S has a
24.0MP Full frame (36 x 24 mm ) sized BSI-CMOS sensor and features Maestro III processor.
Leica SL2-S's sensor provides 10MP more than Samsung ST80'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.
One other difference between these two cameras that is worth mentioning is that Leica SL2-S's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the ST80 and SL2-S sensor size comparison.
As seen above, Leica SL2-S has a 31.2x Larger sensor area than Samsung ST80. 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.