Electromagnetic Radiation

"Energy propagated as time-varying electric and magnetic fields. These two fields are inextricably linked as a single entity since time-varying electric fields produce time-varying magnetic fields and vice versa. Light and radar are examples of electromagnetic radiation differing only in their wavelengths (or frequency). Electric and magnetic fields propagate through space at the speed of light." (National Aeronautics and Space Administration, 2017)

Sources

"Glossary". Earth Observatory, National Aeronautics and Space Administration. Last modified August 4, 2017.
https://www.earthobservatory.nasa.gov/glossary/all.
Accessed February 14, 2019.