Default configuration for anonymous access is preconfigured and stored in the Application Model.
Security system is used to manage the access. Anonymous user and Anonymous role are created automatically although admins are free to define their own objects.
Web application will login anonymous user automatically if AnonymousAuthentication is enabled. Login option will be visible under the Anonymous user name.
Windows client can login Anonymous user the same way as the others.
Anonymous role parameters are for the admin to define and decide what public/anonymous users can view.