Numbers in man pages
 

let's say i write man blah..
it appears in most cases that there is a number along with the commands like command_name(n)
what does that n mean ???

Section 1 user commands
Section 2 system calls
Section 3 library functions
Section 4 special files
Section 5 file formats
Section 6 games
Section 7 conventions and miscellany
Section 8 administration and privileged commands

Some manual entries exist in more than one section. For example 'kill' is both a user command and a system call. To see the respective version, type:
man 1 kill
or
man 2 kill

Regards
Martin