Use On/Off when you want to work with the original function curve rather than a curve altered by ease and multiplier curves.
            A disabled curve has no effect on its assigned track, but can be enabled to restore the effect.
         
          
            Procedures
            
 
            To toggle the active state of an ease or multiplier curve:
            
            
               - In the Hierarchy list, highlight one or more ease or multiplier curves.
- From the Curves menu choose On/Off.
                  If you also have the parent track selected (the transform that has the ease applied), you will see the difference in the curve
                     when you turn the ease or multiplier off.