There are three scientific phenomena that occur as electromagnetic waves encounter a material:
Absorption
Energy loss as electromagnetic waves pass through. This energy loss is usually converted to thermal energy. Absorption is highly dependent on the thickness and magnetic properties of the shield.
Reflection
Energy reflection when electromagnetic waves encounter a material. Reflection can occur from both the front and back surfaces and within the material, independent of the materials thickness.
Transmission
Energy passing through a material with minimal disturbance.
