How can I edit a photo and retain both the original and edited one

Editing in Photos on the iPhone is lossless. You can always revert to the original.

https://help.apple.com/iphone/11/#/iph96b1e322https://help.apple.com/iphone/11/#/iph96b1e322

(. After you edit a photo and save your changes, you can revert to the original image. Tap the image, tap Edit, then tap Revert.)

To restore the original and keep the edits, duplicate the photo before reverting to the original.

Duplicate the photo first.

Thanks! But how do I duplicate an existing photo? Sorry to be so lame!

Select the photo or video in Photos in the browser, then use the command "Image > Duplicate ... photo" or simply press the key combination ⌘D .

Photos does not actually duplicate the photo, but creates a second version for editing, linke to the original stored already in the library. So you do not need much extra storage for the second version.

Click on the link of my previous message.