An short introduction. The human brain is extremely complex. There is more to the brain that scientist do not know than what they do know. Measuring and manipulating brain waves is just one small aspect of the brain and brain research. Learning about the various brain waves is just one small aspect of EEG biofeedback.
Brain waves are frequencies of electrical energy that the brain produces.
This total frequency is broken down in to specific frequency ranges. To understand the concept lets look at light. White light or visible light is a mixture of colors. These colors can be seen through a prism and their wavelengths measured. Light wavelengths are measured in nanometers.