Here's why:

* Transverse waves have oscillations that are perpendicular to the direction the wave travels.

* Longitudinal waves have oscillations that are parallel to the direction the wave travels.

Think of a rope:

* Transverse wave: You shake the rope up and down, creating a wave that travels horizontally along the rope. The wave's motion is perpendicular to the rope's movement.

* Longitudinal wave: You shake the rope back and forth, creating a wave that travels horizontally along the rope. The wave's motion is parallel to the rope's movement.

Examples of transverse waves:

* Light waves

* Water waves

* Waves on a string

Examples of longitudinal waves:

* Sound waves

* Seismic P-waves (pressure waves)