This indicator generates and alert and plots (if enabled), when a divergence is detected. For example, if (above zero) and two crosses are detected with the second being lower than the first, a divergence alert is triggered. Theoretically a good place to take profit / possibly enter a short position if you have further confirmation.
Can also be configured to include continuation signals i.e. a with two crosses where the second is higher than the first. This could indicate more action ahead.
In order to illustrate how this indicator helps to sift out a good amount of false signals, I have highlighted in the above image in dark green, all of the divergence buy signals highlighted by the indicator and in light green, the rest of the buy signals.