You can undo your recent actions, redo them, or revert the changes you've made to a photo all at once.
Undo the last action: Tap or two-finger tap the screen. Tap multiple times to undo up to 200 of your recent actions.
Redo the last action: Touch and hold , then tap Redo, or three-finger tap the screen. Repeat that if you'd like to redo more than one action.
Revert changes: Tap to revert all the changes you've made to a photo in the current and any of the previous editing sessions. On iPhone, touch and hold , then choose Revert to Original. You can also touch and hold a photo directly in the Photos browser to choose Revert to Original from the Quick Actions menu.
Cancel changes and quit: If you'd like to quit the photo without saving any of the edits you've made, tap Cancel orin the top-left corner of the screen and choose Discard Changes.