A cropped photograph may fit an invitation perfectly. A later print might need the wider composition again. If you keep only the edited output, removed image areas cannot simply be recovered. Separating the original, the editable state, and the exported result preserves those options without turning every small adjustment into another confusing pile of files.
Preserve three different things
The original is the unchanged file from the camera or phone. The editable state may live in a project file, a database, or accompanying settings files. The output might be the JPEG exported for a particular purpose. These three components are not interchangeable.
Nondestructive editing generally retains the source image and stores adjustments separately. That only helps if the associated library or settings are backed up too. Copying the original image alone does not necessarily preserve the changes you made later.
Name exports for their use
Keep reduced web images, print outputs, and personal variations in an export area. A name such as birthday-invitation-landscape.jpg says more than image-new.jpg. Preserve the relationship to the original through a shared base name or a documented selection.
Do not overwrite the only original during export. Before a large batch operation, check the destination, filename pattern, and overwrite behavior. A small two-image trial often reveals whether the application is modifying files in the wrong place or removing metadata you intended to retain.
One image for two different uses
A family photograph is first cropped into a square for an invitation. Later it needs to span a wide photo-book page. The square output no longer contains the removed areas at the sides. Keeping the original allows a different crop without trying to turn the small sharing copy into an apparently larger source.
For substantial editing, preserve the editable state too. It may hold separate retouching or color adjustments. Establish whether that requires a project file or the complete library. A clearly labeled export folder can then hold several finished outputs without confusing them with the unmodified source material.
Prepare for leaving the application
Photo services distinguish between downloading an edited view and exporting unmodified originals. Apple explicitly documents an unmodified-original export. Check which version your service supplies and whether you need to export both forms.
Open several exported pictures in another application and inspect dimensions, color, and visible edits. Some formats have additional associated components. Keep a short explanation of the arrangement, and back up originals along with the editing information you need. You can then create a different output later without depending entirely on one app or an already reduced copy.