Predefined Services offers details on a small handful of predefined services such as Domains and Trusts, Networking, Exchange Server, etc. The option queries all required ports for the specified services and displays them in the window of the UI. For those who don't know where Predefined Services resides, it is directly under the Help tab and in the UI. Both serve different needs. The Help tab option immediately displays all predefined services without testing any ports. It is a quick reference to each port name, value, and protocol used for each listed service. The UI option lets you specify what service you want to view and see port statuses.