The ProfileSection.PropertySettings property is a System.Web.Configuration.RootProfilePropertySettingsCollection that provides a collection of System.Web.Configuration.ProfilePropertySettings objects and a collection of System.Web.Configuration.ProfileGroupSettings objects, each of which provides a named collection of other System.Web.Configuration.ProfilePropertySettings objects. These collections are used by the ASP.NET compilation engine to dynamically generate a class called ProfileCommon, which is derived from System.Web.Profile.ProfileBase. The properties of the ProfileCommon class consist of the properties defined in the two collections. In addition, each group property of the ProfileCommon class will contain its own properties, as defined for that group.