Nikon D780 Reference Manual page 187

A
Predictive Focus Tracking
If AF-C is selected for AF mode, or if AF-A is selected and the camera is
shooting using AF-C, the camera will initiate predictive focus tracking if
the subject moves toward or away from the camera while the shutter-
release button is pressed halfway or the AF-ON button is pressed. This
allows the camera to track focus while attempting to predict where the
subject will be when the shutter is released.
Shooting Settings
141