Is this the non-logged in guest user?
Usage
$bool = $user->isGuest();
Return value
bool
API reference based on ProcessWire core version 3.0.236
“We chose ProcessWire because of its excellent architecture, modular extensibility and the internal API. The CMS offers the necessary flexibility and performance for such a complex website like superbude.de. ProcessWire offers options that are only available for larger systems, such as Drupal, and allows a much slimmer development process.” —xport communication GmbH