Your home or car's window, while giving you a natural view of the outside world, protects you from the elements such as rain, snow, wind, etc. If the window is not tinted, it can allow almost 90% of harmful UV rays, heat, and light to enter.
The benefit of a tinted window is that once the film is applied, it can block almost 80% of the sun's radiation. This is accomplished by the presence of special dyes, metals, or nano technology within the film. They help in absorbing or reflecting the sun's energy that makes contact with the glass. Of course, the kind of window film being used plays a huge role in determining its effectiveness.
For instance, dyed films, which are non-metallic, absorb solar energy since they are non-reflective. Hence, they aren't the best choice for controlling heat radiations. Metallized or nano films, on the other hand, offer heat absorption and reflectance. This makes them ideal for solar control since they're built to control heat and light from passing through the glass.