Looking at man pages

One of my friends was asking how to look into the correct man page.

The Unix man pages are generally divided into the following sections.

Section     Description
1     General commands
2     System calls
3     C library functions
4     Special files (usually devices, those found in /dev) and drivers
5     File formats and conventions
6     Games and screen savers
7     Miscellanea
8     System administration commands and daemon

You can look in various sections

$ man  5 passwd
$ man 1 passwd

The first command above gives you details about the structure of /etc/passwd, whereas the second command above will give you details about passwd command.
If you want to get all man page sections , you must install the following packages on (
debian/ubuntu)

manpages-dev - Manual pages about using GNU/Linux for development
manpages - Manual pages about using a GNU/Linux system

You can also try installing the package funny_manpages