Electromagnetic field is a physical field that caused by interaction of electrically charged object. It is one of the four fundamental force in nature that can indefinitely expanse in space. The other fundamental interaction in nature other than electromagnetic field is strong interaction, weak interaction and gravitation . Electromagnetic field is the combination of electric field and magnetic field. Electric field is produces through stationary charge and magnetic field is produces by moving charges. Maxwell equation and Lorentz Force law explains how electric field and magnetic field interact to produces electromagnetic field. Though, according to quantum field theory, field is seen as a quantized, electromagnetic field is continuous and propagate in smooth manner. Read more in bellow link Electromagnetic force http://zipansion.com/2bpC1 Electromagnetic radiation http://zipansion.com/2Nbk8 Electromagnetic field http://zipansion.com/2bp6i