Light rays which are reflected by any surface become polarised and polarising filters are used to select which light rays enter lens, allowing removal of unwanted reflections from non-metallic surfaces such as water, glass etc.
a)Specially polarizer designed not to interfere with rotating auto focus lenses
b)Also enables colors to become more saturated and appear clearer, with better contrast.
c)The effect is often used to increase the contrast and saturation in blue skies and white clouds.
d)Does not affect the overall color balance of a shot.