iCloud Photos is a synchronization service, not a storage archive. It mirrors your photos across your devices, ensuring your Mac’s Photos library and iCloud Photos library display identical content. Adding a photo on your Mac adds it to iCloud, and deleting a photo on your Mac deletes it from iCloud. Crucially, deleting photos on your Mac means permanently losing them, even though they initially move to the Recently Deleted album, allowing for potential recovery.
While iCloud Photos doesn’t inherently free up space on your Mac, it offers an “Optimize Mac Storage” option. This feature stores smaller image versions locally, keeping full-sized files in iCloud Photos, potentially saving significant space (possibly over 100GB) over time, though not instantly.
Synchronization can take several days. Potential roadblocks arise from incompatible image or video formats, especially with videos due to evolving codecs. Identifying problematic files can be tricky. One method involves creating a Smart Album using specific criteria, though pinpointing these files often requires further investigation.
