man - What is the meaning of the number in parens after the names of shell commands in the title of a manpage? -

I see these numbers everywhere. For example, on this page:

What does the number mean - 1 in tar (1) ? I have also seen 2, 5, etc.

It tells you what the group is in its manpage or, more generally, the group itself Here is a list of sections and their contents:

  1 executable program or shell command2 system call (task provided by the kernel) 3 library calls (functions in program libraries ) 4 special files (usually found in / dev) 5 file formats and conferences eg / et C / passwd 6 Games 7 Miscellaneous (including macro packages and conventions), e.g. For more information see Man of Man page. 9 kernel routine [non-standard]   
 For more information see Man's Man Page. Or here's a look:  
 Occasionally, different group items can have the same name and this is the method of distinguishing between them. For example, there is a manup for  printf (1) , which is executable, is collabel with shell, as well as a man page for  printf (3)  Which is C definded the function in Stdio.h.  
 By using a bass man binary, you can call different manpages:  
  man displays printf # printf (1) man 1 Printf # Displays printf (1) man 3 prinft # displays printf (3) man -a printf # displays all manpages matching printf   
 Which manages installed on the system Depending on whether you ever receive a page for a single item from a different manual, for example, Linux Progr Die manual  printf (3)  a  printf (3p)  can be equivalent