What is the difference between a compression and a rarefaction in a sound wave? Illustrate your answer with a sketch.

The part of a longitudinal wave in which the particles of the medium are closer to one another than they normally are, and there is a momentary reduction in the volume of the medium, is known as compression.

The compression is a region of high pressure.

The part of a longitudinal wave in which the particles of the medium are farther apart than normal is known as rarefaction, and there is a momentary increase in the volume of the medium.

The rarefaction is a region of low pressure.