Electromagnetic radiation (EM) is a wave having electric and magnetic components, which propagates itself through space. Most EM is invisible. EM has both energy and momentum. Light is an example of EM, and light transfers its energy into heat when it collides with something, such as a person.
The electric and magnetic components of an EM wave oscillate at right angles to their direction of travel, and at right angles to each other.
EM is classified based on the frequency of the oscillation of its wave. From low to high frequency, EM waves are classified as radio waves, microwaves, terahertz radiation, infrared, visible light, ultraviolet, X-rays and gamma rays.