It is used in Linux long directory listings. It consists of 10 characters. The first character shows the file type. Next 9 characters are permissions, consisting of three groups: owner, group, others. Each group consists of three symbols: rwx (in this order), if some permission is denied, then a dash "-" is used instead. Example:
-rwxr--r--
0123456789
* Symbol in the position 0 ("-")is the type of the file. It is either "d" if the item is a directory, or "l" if it is a link, or "-" if the item is a regular file.
* Symbols in positions 1 to 3 ("rwx") are permissions for the owner of the file.
* Symbols in positions 4 to 6 ("r--") are permissions for the group.
* Symbols in positions 7 to 9 ("r--") are permissions for others.
r Read access is allowed
w Write access is allowed
x Execute access is allowed
- Replaces "r", "w" or "x" if according access type is denied