Editing Computer file (section)

==Protection==
Many modern computer systems provide methods for protecting files against accidental and deliberate damage. Computers that allow for multiple users implement [[file permissions]] to control who may or may not modify, delete, or create files and folders. For example, a given user may be granted only permission to read a file or folder, but not to modify or delete it; or a user may be given permission to read and modify files or folders, but not to execute them. Permissions may also be used to allow only certain users to see the contents of a file or folder. Permissions protect against unauthorized tampering or destruction of information in files, and keep private information confidential from unauthorized users.

Another protection mechanism implemented in many computers is a ''read-only flag.'' When this flag is turned on for a file (which can be accomplished by a computer program or by a human user), the file can be examined, but it cannot be modified. This flag is useful for critical information that must not be modified or erased, such as special files that are used only by internal parts of the computer system. Some systems also include a ''[[Hidden file and hidden directory|hidden flag]]'' to make certain files invisible; this flag is used by the computer system to hide essential system files that users should not alter.