This document discusses different types of wave motion. It explains that wave motion occurs as a disturbance that transfers through a medium via the periodic motion of its particles. Elastic or mechanical waves require a physical medium to propagate, while electromagnetic waves do not. The document then describes transverse wave motion, where particles vibrate perpendicular to the direction of propagation, and longitudinal wave motion, where particles vibrate in the direction of propagation. Diagrams provide examples of transverse waves and the compression and rarefaction of longitudinal waves. References for the pictures and information are listed.