Inode stores basic information about a regular file, directory, or other file system object. The inode number is a unique integer assigned to the device upon which it is stored. All files are hard links to inodes. Whenever a program refers to a file by name, the system conceptually uses the filename to search for the corresponding inode. Many computer programs often give i-node numbers to designate a file. Popular disk integrity checking utilities fsck or pfiles command may serve here as examples.