Introduction to Waves

After reading this section you will be able to do the following:

  • Name the three categories of waves.
  • Provide examples of mechanical and electromagnetic waves.

There are three primary categories of waves:

  1. Mechanical
  2. Electromagnetic
  3. Matter

Each of these categories of waves breaks down into additional types of waves. In this module we'll discuss mechanical waves and electromagnetic (EM) waves. Matter waves are a part of quantum theory and are therefore beyond the scope of this material. Some examples of mechanical and electromagnetic waves are shown below. In the mechanical waves column, we see ripples in a pond and sound. Other examples of mechanical waves are waves on the ocean and seismic waves that occur from earthquakes. In general, mechanical waves are waves that require a medium to travel. In the electromagnetic waves column below we see the sun which produces ultraviolet radiation, a type of EM wave. We also see an antenna which produces EM waves at microwave frequencies. EM waves do not require a medium to travel. In the following pages we'll learn more about the different types of EM radiation, as well as other wave characteristics.

Mechanical Waves Electromagnetic Waves


  1. There are 3 primary categories of waves: mechanical, electromagnetic (EM), and matter.
  2. Mechanical waves require a medium to travel while EM waves do not.