-Permanently destroying or altering pixels/images
-Cropping an image without saving a safe copy is destructive
-You are able to return to a previous unedited/unaltered state of the image whenever you want
-Creating a new layer and using the spot healing brush while sample all layers is on is an example of Non-Destructive editing.
-Using masks helps with Non-Destructive editing.
We used both Destructive and Non-Destructive editing to replace the sky in this cityscape/skyline. We used selections and masks to isolate the sky, we then proceeded to use the gradient tool to create a new sky.
When zoomed in, my selections and use of masks was slightly sloppy, so I need to work on using the tools for masks and selections more and perfect my editing of those masks and selections.