What is Bollinger Bands?

What is Bollinger Bands. Bollinger Bands created by John Bollinger in the early 1980s to assist the technical analyst can predict price approach for the upcoming destinations that benefit from its analysis and estimate the possible risks that may arise. Bollinger bands itself actually consists of three lines which form a barrier to the movement of the belt. However, in its application to the center line of the Bollinger Bands are often not shown because it is the middle line is the line of ordinary Moving Averages. Consider the following picture:

In the picture below is the Bollinger bands on the EURO currency by using the time frame H4