Electromagnetic (EM) waves consist of oscillating electric ($\vec{E}$) and magnetic ($\vec{B}$) fields.

• $\vec{E}$ and $\vec{B}$ oscillate in directions perpendicular to each other.
• Both fields are also perpendicular to the direction of wave propagation ($\vec{k}$).
• Since the oscillations are perpendicular to the direction of travel, the waves are characterized as transverse.