A great example of this is a system recovery partition. Usually, a recovery partition houses critical backup and recovery files for the main system OS, such as Windows. If and when the operating system experiences a critical failure, whether from normal use or malicious means, like malware, you can use the recovery partition content to restore a clean backup. But in order to make sure that possible, the recovery partition is usually hidden and made inaccessible or unwriteable under normal means...
