Data corruption is the damage of info due to various hardware or software failures. The moment a file gets damaged, it will no longer work as it should, so an app will not start or will give errors, a text file will be partially or entirely unreadable, an archive file will be impossible to open and unpack, etc. Silent data corruption is the process of information getting damaged without any identification by the system or an admin, that makes it a serious problem for web hosting servers as fails are much more likely to occur on bigger hard disk drives where significant volumes of info are kept. In case a drive is a part of a RAID and the information on it is replicated on other drives for redundancy, it is more than likely that the damaged file will be treated as an ordinary one and it will be duplicated on all the drives, making the harm permanent. A huge number of the file systems that operate on web servers these days often are not able to discover corrupted files instantly or they need time-consuming system checks through which the server is not working.