Book excerpt: Brain waves are oscillating electrical voltages in the brain measuring just a few millionths of a volt. It takes time to understand every aspect of the brain waves for people who want to research. If you are one of those, read this book! This e-book offers a concise and informative overview of brainwaves and their frequencies. Learn more about how your brain works by understanding the differences between the five different brainwave frequencies, and how they are related to specific states of mind. During the course of the book, we will explore: The history of the science of brainwaves. How your brainwave frequencies change as you go through the sleep cycle. How you can change your brainwaves using diet, brainwave entrainment, binaural beats, or meditation. Different theories of consciousness and how they relate to our understanding of brainwaves.