Traditional photo editing is ‘destructive’. That means every adjustment you make permanently changes the pixels in the photo and there’s no way back unless you’ve saved a copy of the original and you’re willing to start again. ‘Non-destructive’ editing is fully reversible. You can go back and undo or redo all of your editing work at any point in the future. Naturally, there’s a catch
Any information embedded in a digital photo. It can include time, date and shooting information (EXIF data) embedded by the camera, keyword, caption and copyright (IPTC data) added by image cataloguing programs and, sometimes, image processing data added by non-destructive image-editing programs.