14. what is electromagnetic radiation?
the relationship between the direction of changing waves and the angles of the fields
the transfer of energy by electromagnetic waves traveling through matter or across space
the region of space that exerts electric forces on charged particles
the regeneration of electric and magnetic fields

The transfer of energy by electromagnetic waves traveling through matter or across space

Explanation:

Electromagnetic radiation is a combination of oscillating electric and magnetic fields, which propagate through space carrying energy from one place to another.  

To understand it better:  

This radiation is spread thanks to the electromagnetic fields produced by moving electric charges and their sources can be natural or man-made.  

It should be noted that the energy of electromagnetic radiation can vary and depending on its frequency it can be useful for various situations.