What type of wave has energy that moves perpendicular to its direction?

A transverse wave is characterized by the movement of energy that travels perpendicular to the direction of the wave itself. In simpler terms, if you imagine waves moving across a surface, the energy moves up and down while the wave travels forward.

This is most evident in scenarios like ocean waves, where the water surface moves in an up-and-down motion while the wave moves horizontally along the water's surface. Examples of transverse waves also include light waves, which consist of oscillating electric and magnetic fields that are oriented at right angles to the direction the wave travels.

In contrast, longitudinal waves, such as sound waves, feature energy that moves parallel to the direction of wave travel; energy compresses and decompresses in the same direction the wave is moving. Mechanical waves, which can be either longitudinal or transverse, require a medium to travel through, while surface waves incorporate elements of both transverse and longitudinal behavior but are still defined distinctly from transverse waves. Thus, the nature of energy movement in transverse waves distinctly sets it apart from the other types mentioned.