The document provides troubleshooting steps for fixing issues with iPhone photos not syncing to iCloud, Mac, or PC, identifying potential causes such as unreliable internet or disabled iCloud photo settings. It outlines specific methods to address these issues, including checking network connectivity, managing iCloud storage, and ensuring consistency in Apple ID across devices. Additionally, it introduces third-party software, Isumsoft BackupTo, as an alternative tool for seamless photo transfer and backup.