File copying is a basic function of file system management, supported on all systems. It creates a byte-for-byte identical destination file based on the source file. Various command line interfaces have different commands for file copying. DOS-based systems use "copy", while systems derived from UNIX use "cp". File moving is a closely related concept in which a file is copied to a destination and the source file then deleted.
All questions that are known to involve a failure of a file copy or file move should be tagged with this. Common causes of failure are bad syntax, corrupt source or destination filesystems and lack of permissions.