The two most common notations for permissions is the textual notation and the octal notation. Each one has its own virtues.
The textual notation is traditionally used in UNIX long directory listing format and in most FTP clients listings as well. It consists of ten characters. The first one displays the file type. It can be one of dash (regular file), "d" (a directory) or "l" (a link). The following nine characters display the permissions, consisting of three groups of three letters each. The groups are in order of appearance: owning user, owning group and others. The permissions on each group are in order of appearance: read (denoted with r), write (denoted with w) and execute/browse (denoted with x). If a permission is not set, a dash appears instead of the letter.
For example, the string
-rwxr-xr-x means that it is a
regular file, the owning user has read/write/execute permissions,
the owning group has read and execute permissions and so does the
rest of the world. On the other hand, the string
dr-x------ indicates that we have
a directory whose owning user has read and browse permissions and
everybody else (owning group and the rest of the world) have no
right to access it.