If I am correct, ESS is the union of a set of BSS's. ESSID and BSSID are just their IDs respectively.

How can I tell if a wireless network has essid, bssid or ssid?
What differences are between usages of essid, bssid and ssid? When to use which?

Which one should apply to the wireless network created by my router in my apartment: ESSID, BSSID, or SSID?

Some examples of commands that use ESSID, BSSID or SSID as their arguments. But I am not sure why they use one not the others.

1. The manpage of iwconfig says

   
   
   

   NAME
   
          iwconfig - configure a wireless network interface
   
   
   
   SYNOPSIS
   
          iwconfig [interface]
   
          iwconfig interface [essid X] [nwid N] [mode M] [freq F]
   
                             [channel C][sens S ][ap A ][nick NN ]
   
                             [rate R] [rts RT] [frag FT] [txpower T]
   
                             [enc E] [key K] [power P] [retry R]
   
                             [modu M] [commit]
   
          iwconfig --help
   
          iwconfig --version
   
   

   
   
   

   Why does it have an argument essid rather than bssid? Does a
   wireless network interface always work with a ESS not a BSS?




2. wpa_cli has a command

   
   
   

      bssid <network id> <BSSID>
   
             set preferred BSSID for an SSID
   
   

   
   
   

   Why does it use BSSID instead of ESSID as iwconfig does?




3. wpa_passphrase uses an argument for a SSID, does it mean the
   argument can be either BSSID or ESSID?

   
   
   

   SYNOPSIS
   
          wpa_passphrase [ ssid ] [ passphrase ]
   
   




4. wicd-wired-settings.conf has the following settings:

   
   
   

      bssid = <BSSID_of_network>
   
             This value can be found using iwconfig(8).
   
   
   
      essid = <ESSID_of_network>
   
             This value can be found using iwconfig(8).
   
   

   
   
   

   Can iwconfig tell if a network is ESS or BSS?

Thanks!