Amplitude, wavelength, period, frequency and phase difference. Reflection, refraction, diffraction, interference and polarisation. Any vibrating body that is connected to its environment will transfer energy to its environment. The vibrations are then transferred though the environment from neighbour to neighbour. This energy transfer is called wave motion.
Waves move energy through a medium without moving the whole medium.
Types of waves Longitudinal waves When waves transfer energy by pushing neighbours in the same direction that the energy moves, the waves are called longitudinal waves. The places when the particles cluster together are volumes of high pressure so these waves are also called pressure waves. Sound waves are an example of pressure waves and they can move through gases, liquids and solids. For sound waves, the denser the medium the faster the speed. When waves transfer energy by pulling neighbours sideways to the direction of travel, the waves are called transverse waves.