This document discusses electromagnetism and electromagnetic waves. It explains that electricity and magnetism are two aspects of the same electromagnetic force. Changing electric fields create magnetic fields and vice versa. Maxwell's equations showed that electric and magnetic fields propagate as electromagnetic waves. These waves can transfer energy and information over long distances through empty space in the form of radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. The different types of electromagnetic waves are distinguished by their frequencies.