Essentially what this script signifies are price breakouts when price crosses over the upper BB band. So what it shows is that market conditions are entering overbought territory.
Length is set to 20 and Standard Deviation is set to 2. These are the default settings.
The way I use the script is to identify breakouts in price, as well as a signal to start scaling out of a position if I am already in one.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.