Bollinger Bands are a technical analysis tool created by John Bollinger, consisting of a middle band (the simple moving average) and two outer bands (standard deviations above and below the moving average). These bands help traders identify potential overbought or oversold conditions in a security's price, as well as market volatility. When the price moves closer to the upper band, it may indicate that the asset is overbought, while a move towards the lower band may suggest it is oversold. The width of the bands also varies with volatility; narrower bands indicate lower volatility and potential price breakouts, while wider bands suggest higher volatility.