John Bollinger, who is a trader invented Bollinger Band for technical analysis of trades. In 2011, the term Bollinger Band® is trademarked by him.
Bollinger Bands means plus or minus two standard deviations where the standard deviations are calculated historically in a moving window estimation. Hence, the bands will widen if the most recent data is more volatile. If the prices break out of the band, this is considered a significant move.
Bollinger Band is designed to provide traders with information regarding price volatility. It is used as a tool by traders to take systematic trading decisions.