UNIX refers to all files and directories by an inode number. This inode number is actually an entry number in an inode table. Each file system has its own inode table, and each inode entry in use contains information about one file in that file system. An inode entry contains most of the information about a file, such as the owner, group, permissions, type of file, date/time of last access, date/time of last modification, and so on. You might be surprised to learn that the inode table entry contains everything about the file except for the filename.
A directory is a file under UNIX that has two purposes:
To keep track of the filenames and subdirectory names contained in that directory
To keep track of ...