All current paints are subject to the effects of sunlight, water, and air.
All three eventually cause the paint to loose its shine. A paint that is unprotected and uncared for will eventually develop a chalk-like appearance. Paint in this condition has oxidized. This process can be slowed by cleaning and protecting the car's paint with products such as cleaners, polishes, and wax. A cleaner is a material used to remove the top layer of oxidized paint.