There are 2 major categories of waves, mechanical waves and electromagnetic waves. Some examples of the mechanical waves include sound waves, gravity waves (in the ocean), and surface waves (like a rock in a pond). Some examples of electromagnetic waves include radio waves, visible light, x-rays, and brain waves. The world is formed and moved by waves.
Visible light only comprises 0.0035% of the electromagnetic spectrum, which means we have the tiniest crack of window through which to see this world. Everything else is beyond us. We can try to detect the unseen, and harness it to our benefit, but ultimately we are feeling our way through the dark.
What matters more than these categories and facts is that there is a very vast and very real world that we cannot perceive through our usual five senses. Learning more about this has given me reverence for the unknown, and has made me more aware of the energy I transmit. Everything that life touches is in constant communication. An individual can tune in to whatever frequency they choose.