A wave is a repeating disturbance or movement that transfers energy through matter or space. Waves are caused by vibrations.
There are two types of waves, transverse, and longitudinal waves.
The moving particles in transverse waves travel at right angles to the direction of transverse. Some examples of transverse waves are light waves and radio waves.
A longitudinal wave is also known as a compression wave. The moving particles move back and forth in the same direction as the wave. An example of this is a wave moving through a stretched out slinky.
Image 1: There are two areas in a longitudinal wave, a compression, and a rarefaction. A compression is created when particles are pushed together, while a rarefaction is created