horde.php config file

[lbelon at etud.insa-tlse.fr]

Hello!

   I've just installed Horde-1.3.5  and IMP-2.3.7 with
all the needed components. My database support is MySQL.

   I'm trying to configure all the options of the
/horde/config/*.php files to match my system.

   In the horde.php file, the "Horde Authentication"
section seems mysterious, I don't understand the aim of  

// What backend should we use for authenticating users
to Horde? Valid
// options are currently 'imap', 'ldap', 'mcal', 'sql',
and 'ftp'.
$conf['auth']['driver'] = '';

// An array holding any parameters that the Auth object
will need to
// function correctly. For IMAP, this is the server
name, port,
// protocol, etc.
$conf['auth']['params'] = array();

   I wonder if these options can be left empty.
	
   Could someone answer me and explain what is this
authentication?


   Thanks.