Here you can change the network settings such as Automatic or Manual IP address (default set to Automatic), Use Automatic or Manually DNS server and change the default port settings for HTTP, RTSP, RTP, RTMP also you can enable or disable password protection for the RTSP video stream (default set to enabled and will use the same credentials as set in the user account settings).
If you wish to access your ca.mera using a Dynamic DNS server like for example DYNDNS or NO-IP you can enable and configure this feature here as also enable/disable UPnP port mapping
Here you can change the Onvif settings (Open Network Video Integration Forum)
The ONVIF specification defines a common protocol for the exchange of information between network video devices including: automatic device discovery, video streaming and intelligence metadata.
The Preview option is to enable or disable a password when using the Onvif protocol. By default, this is enabled (user name and password correspond to the user settings of the camera).