Sections of the manual pages

       The manual Sections are traditionally defined as follows:

       1 Commands (Programs)
                 Those commands that can be executed by the user from within
                 a shell.

       2 System calls
                 Those functions which must be performed by the kernel.

       3 Library calls
                 Most of the libc functions.

       4 Special files (devices)
                 Files found in /dev.

       5 File formats and conventions
                 The format for /etc/passwd and other human-readable files.

       6 Games

       7 Overview, conventions, and miscellaneous
                 Overviews of various topics, conventions and protocols,
                 character set standards, and miscellaneous other things.

       8 System management commands
                 Commands like mount(8), many of which only root can
                 execute.