Photo files can become corrupted for a few common reasons: storage media can degrade over time, and read/write errors can cause silent data corruption. A single bad bit can be enough to damage an image, whether the file is on a hard drive or SSD.

You can’t guarantee that a drive will never fail, so the practical solution is protection and detection:

• Keep multiple copies of your photos.
• Store backups on separate drives.
• Keep at least one copy in a different physical location or use a reputable online storage service.
• Use checksums or another file-integrity method so you can detect corruption instead of unknowingly backing up a damaged file.

Backups alone are not always enough if corruption is copied to every backup, so integrity checking matters. More technical users can also look at filesystems with built-in data-integrity features.

In short: corruption happens because storage is imperfect; the best defense is redundant backups plus a way to verify file integrity.