This is a two-part answer; first, therapy is electromagnetic radiation delivered at a specific frequency range, also known as radio waves. Electromagnetic radiation surrounds us, coming from such sources as lightning, the stars, the sun, and our bodies. They span quite a range of frequencies and wavelengths. Frequency relates to the number of cycles formed in one second and is measured in Hertz; a wavelength describes the distance between two wave peaks.

Second, we divide radio frequency into bands ranging from low to high. Low frequencies, such as those used for sending data and voice communications, travel longer distances. High frequencies, on the other hand, transmit just a short distance. Higher frequencies are those used to treat the human body in both medicine and aesthetics.