If you leave these blank, then defaults will be used.
In either case, the user will be able to edit all of these fields after they log in.
Specify the format that the password field is using.
Use \'internal\' if you want the external database to manage usernames and email addresses, but Moodle to manage passwords. If you use \'internal\', you must provide a populated email address field in the external database, and you must execute both admin/cron.php and auth/db/cli/sync_users.php regularly. Moodle will send an email to new users with a temporary password.