Which of the following best describes an electromagnetic wave?

An electromagnetic wave is accurately described as a wave of electric and magnetic fields that travels through space. This is due to the fundamental nature of these waves, where electric fields and magnetic fields oscillate perpendicularly to each other and to the direction of wave propagation. This characteristic allows electromagnetic waves to travel through the vacuum of space without the need for a physical medium, unlike mechanical waves, which require a medium (like air, water, or solids) to move through.

The essence of electromagnetic waves includes a range of phenomena such as light, radio waves, and X-rays, all of which exhibit this behavior of oscillating electric and magnetic fields. Therefore, the choice that highlights both components—electric and magnetic fields—traveling together is the most accurate description of electromagnetic waves.