Transverse waves make the particles of the wave travel perpendicular to the direction of energy transfer. Examples of transverse waves include light waves and seismic S waves.
Longitudinal waves have particle oscillations that are parallel to the direction of energy transfer in the wave. Examples of longitudinal waves include sound waves and seismic P waves.
Different types of waves can be categorised depending on different characteristics: the presence of particles, the orientation of particle movement and the direction of energy transfer. The two main types of wave are electromagnetic and mechanical waves; mechanical waves can be broken down further into transverse, longitudinal and surface waves.
Sound waves are longitudinal waves; some frequencies can be heard by humans, but others are out of the range of human hearing.
Seismic waves are created by earthquakes, and they travel through the different layers of the earth. There are two types of Seismic waves: P waves, that are longitudinal, and S waves that are transverse.