Which type of phenomenon (reflection or refraction) occurs when light falls on (i) a highly polished surface like a mirror and (ii) a transparent medium like glass or water?

(i) When light falls on a highly polished surface like mirror, reflection occurs. 

(ii) Refraction of light occurs when light falls on a transparent medium like glass or water. When there is diffrence in the density of the medium, a ray  tends to bend towards or away from the normal at the interface of media.