Data corruption is the accidental transformation of a file or the loss of information that often occurs during reading or writing. The reason could be hardware or software failure, and because of this, a file could become partially or entirely corrupted, so it'll no longer work properly since its bits will be scrambled or lost. An image file, for instance, will no longer show a true image, but a random combination of colors, an archive will be impossible to unpack as its content will be unreadable, etcetera. In the event that such an issue appears and it's not noticed by the system or by an admin, the data will be corrupted silently and if this happens on a drive which is part of a RAID array where the info is synced between various different drives, the corrupted file shall be replicated on all of the other drives and the damage will become long term. A large number of widespread file systems either don't offer real-time checks or don't have good ones that can detect an issue before the damage is done, so silent data corruption is a common issue on hosting servers where substantial amounts of data are kept.