Both Fujifilm X-T20 and Canon M50 have 24.0 MP resolution sensors but Fujifilm X-T20's sensor is APS-C (23.6 x 15.6 mm ) and Canon M50's sensor is APS-C (22.3 x 14.9 mm ).
Since Fujifilm X-T20'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 Canon M50.
Another difference between these two cameras is that Fujifilm X-T20's sensor lacks 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 moire occurring in certain scenes.
Below you can see the X-T20 and M50 sensor size comparison.
As seen above, Fujifilm X-T20 has a 1.1x Larger sensor area than Canon M50. 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.