What is it used for?

The Update SSID sub-panel allows to change the SSID parameter, which is the ID name associated to the Wi-Fi of the location. 
This setting is useful for the administrator to assign the Wi-Fi connection of the structure a name that is familiar and easily identifiable by the guests, so as to make the connection procedure easier.

Update SSID Tools

To change SSID, just click the edit button appearing on the right of the form containing the ID name currently in use. Below, in the form, write the new ID name of the network. 
To save SSID changes, just click the "Save" button on the left side of the screen.