The Application Host Helper Service (AppHostSvc) provides administrative services for IIS, for example configuration history and Application Pool account mapping. If this service is stopped, the IIS configuration history feature will not work, and you will be unable to use Application Pool-specific access control entries to lock down files or directories.
This service is not installed by default. After it is installed, the Application Host Helper Service startup type is Automatic. When the Application Host Helper Service is started in its default configuration, it logs on by using the Local System account.
This service is not dependent on any other system service, nor is any service dependent on it.