The UAApplicationTypes.IsServer extension method allows you to determine whether a UA application (as returned e.g. by server discovery) includes OPC-UA server functionality. This is a shortcut for testing whether the application type is either Server or ClientOrServer.

The extensions on the UANodeElement (as returned e.g. by browsing for OPC-UA nodes) allow finer categorization of the nodes over what is provided just by the NodeClass property. For example, you can test whether a node is a Data Variable or a Property, by extensions methods IsDataVariable and IsProperty.