What are filters? why would you use one?

Art Filters are just one of the fantastic features you can find inside the Olympus OM-D and PEN system cameras. Polarizing filters which are used to reduce glare and improve overall image saturation and UV filters which essentially exist to provide extra protection.

A filter is a thing that cleans something like in some fancy places they filter the air so they can breath the clean air and not have to leave because there allergy to something like pollen or some thing else. they also mainly filter water because of all germs, bacteria, pareisits, ect... in water. the water that you bye at the store has been petrified to the finest of clean.