Is the current thought that brainwaves affects the brain? What's the mechanism for this? They aren't even really waves like we think of radio waves or magnetic

Is the current thought that brainwaves affects the brain? What's the mechanism for this? They aren't even really waves like we think of radio waves or magnetic waves. Saying that brain waves have a "function" like a Scientific American article seems so backwards. I'm a little confused why the language used around them is of casuality.