Synced files are copies stored across multiple devices through a cloud service, which updates them to match when changes occur. Files might appear missing on one device due to temporary connectivity issues preventing download, insufficient local storage space preventing the download from completing, sync errors caused by software conflicts, or platform-specific restrictions like certain folders not syncing to mobile. This differs from manual copying where versions can get out of date.

For example, a user adding large photos to their cloud storage via a laptop might find them missing on their phone if the phone's storage is full. Similarly, shared documents in a team folder might not appear on a colleague's desktop if their sync client crashed or encountered a version conflict that halted updates until resolved.

While syncing offers convenience and access across devices, limitations include reliance on consistent internet, local storage constraints, and potential software glitches causing delays or omissions. Regular manual checks of sync status and storage availability are recommended to identify and resolve such issues quickly, ensuring all intended files are accessible everywhere.