Electromagnetic field

An electromagnetic field (also EM field) is a classical field produced by moving electric charges. Consisting of the combination of the electric field and the magnetic field, it is generated locally by any distribution of electric charge that varies over time and propagates in space in the form of electromagnetic waves.

The electromagnetic field interacts in space with electric charges and can occur even in the absence of them since it is a physical entity that can be defined independently of the sources that generated it. In the absence of sources, the electromagnetic field is called “electromagnetic radiation“ or “electromagnetic wave“; being a wave phenomenon that does not require any material medium to spread in space and that travels at the speed of light in the vacuum.