Data corruption is the damage of information due to various hardware or software failures. The moment a file is damaged, it will no longer work properly, so an app will not start or shall give errors, a text file could be partially or fully unreadable, an archive will be impossible to open then unpack, etc. Silent data corruption is the process of data getting damaged without any acknowledgement by the system or an administrator, that makes it a serious problem for web hosting servers as fails are much more likely to occur on bigger hard drives where large volumes of info are placed. When a drive is part of a RAID and the data on it is duplicated on other drives for redundancy, it is more than likely that the bad file will be treated as an ordinary one and will be copied on all drives, making the damage permanent. A lot of the file systems which operate on web servers today often are not able to discover corrupted files in real time or they need time-consuming system checks during which the server isn't operational.