Electromagnetic waves travel as oscillating electric and magnetic fields that are perpendicular to each other and to the direction of wave propagation. These fields continuously induce each other, allowing the wave to sustain itself and propagate through space without the need for a physical medium

. In a vacuum, electromagnetic waves travel at the speed of light, approximately 3.00×1083.00\times 10^83.00×108 meters per second. The electric and magnetic components oscillate in phase, with the electric field oscillating in one direction and the magnetic field oscillating perpendicular to it, both perpendicular to the direction the wave travels

. When electromagnetic waves pass through a material medium (such as air, water, or glass), their speed is reduced. This happens because the oscillating electric field causes charged particles in the atoms of the medium to vibrate, temporarily absorbing and then reemitting the wave's energy. This absorption and reemission process causes a delay, effectively slowing the wave's net propagation speed through the medium

. In summary:

• Electromagnetic waves consist of mutually perpendicular oscillating electric and magnetic fields.
• They propagate by the continuous induction of these fields, allowing travel through vacuum and matter.
• They travel at the speed of light in vacuum.
• Their speed decreases in materials due to interaction with atoms causing absorption and reemission delays.

This self-sustaining mechanism of oscillating fields is why electromagnetic waves can travel through empty space and through various media