Temperature Graph

Can anyone tell me just what this is, how it works or an example where it will help me while using it fishing. Still trying
to learn some more of the bells and whistles on my sonars. Thanks in advance for any and all help.

Temperature Graph (Sonar View only, with Temperature input) Settings: Off, On, Default = On Temperature Graph allows you to display or suppress a water temperature graph over the main Sonar View to show temperature changes correlated to recent sonar history.