Remote switch has a device attatched that when a button is pressed, will automatically, move the switch points.
Manual, you have to use the old "armstrong" method , by doing it yourself. Atlas has a different "control" for both. The manual one has a pin, that you have to move yourself to align the track. The automatic has the same, just in case.
Maybe someone can post a pic of the difference, as I usually buy the track with out the "throws" on them, and add ground throws from Caboose Industries.