Data corruption is the unintentional change of a file or the loss of info that often occurs during reading or writing. The reason could be hardware or software fail, and because of this, a file can become partially or completely corrupted, so it will no longer function properly because its bits will be scrambled or missing. An image file, for instance, will no longer show a real image, but a random mix of colors, an archive will be impossible to unpack since its content will be unreadable, etcetera. If this kind of a problem appears and it's not recognized by the system or by an administrator, the data will get corrupted silently and in case this happens on a disk drive that's a part of a RAID array where the info is synchronized between various different drives, the corrupted file shall be copied on all other drives and the damage will become long term. A large number of widely used file systems either don't have real-time checks or do not have high quality ones which will detect an issue before the damage is done, so silent data corruption is a common matter on internet hosting servers where large amounts of information are kept.