In which type of wave does the medium move perpendicular to the wave's direction?

In a transverse wave, the particles of the medium move perpendicular to the direction in which the wave travels. This can be visualized by considering waves on a string or water waves, where the peak and trough oscillate up and down while the wave itself moves horizontally. This perpendicular motion is a fundamental characteristic of transverse waves, distinguishing them from longitudinal waves, where the medium's motion is parallel to the wave direction.

Transverse waves can be seen in various phenomena, such as light waves, which are electromagnetic in nature, as well as in sound waves through solids. The clarity of this perpendicular movement helps in understanding wave properties like wavelength and amplitude, which are key in analyzing wave behavior in different contexts.