Enhanced Photo and Video Editing
The iOS 13 update adds in improved photo editing with the ability to see the changes as you apply different filters or edits to the photo in preview mode.
You also get totally new video editing options. On iOS 12 you can trim a video, but that is about it.
With iOS 13 you can rotate a video that is the wrong orientation, apply filters, tap to instantly fix problems like on a photo and more.
Now when you trim and edit a video you will never lose the original, so you can go back to it if you need to start over.