Write protection is a feature of computer storage devices such as hard disk drives, floppy disks, USB flash drives, and memory cards that prevents any changes from being made to the stored data. It can be invoked as either a hardware or software mechanism, and is intended to protect the user’s stored data from accidental or unintentional changes, or from malicious tampering.
When in write-protected mode, any modifications to the data on the device are either blocked entirely, or put in another area of the device which is protected from being accessed. In some cases, write protection may be reversible, while in others it may be permanent.
Hardware write protection is usually enabled by a physical switch or tab which, when activated, prevents any changes from being written to the device. These switches are found on the exterior of the device, usually on the side. Software write protection is generally enabled by a procedure built into the file system that is installed on the device. It can be enabled either through the user interface, or by a command in the command line.
Write protection is commonly used on data storage devices that are intended to be read only, such as memory cards that are part of an electronic control system. In these cases, any changes made to the device would cause the system to malfunction. For other storage devices, write protection can be useful for protecting any sensitive or personally identifiable data from unintentional or malicious changes.
