The Unix man pages are generally divided into the following sections.
You can look in various sections
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
8 System administration commands and daemon
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.
$ man 5 passwd
$ man 1 passwd
If you want to get all man page sections , you must install the following packages on (
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