The namespace contains classes that are used to work with ASP.NET user profiles in Web server applications. ASP.NET profiles are used to store and retrieve user settings in a data source such as a database. Profile information and property values are managed by using a profile provider. Profile information can be stored in a Microsoft SQL Server database by using the class, or in a custom data source by using an implementation of the abstract class. ASP.NET profiles are configured by using the profile configuration section. When an application starts that has profiles enabled, ASP.NET creates a new class of type ProfileCommon, which inherits from the class. Strongly typed accessors are added to the ProfileCommon class for each property that is defined in the profile configuration section. An instance of the ProfileCommon class is set as the value of the property of the current object. You can create a custom profile implementation that inherits from the abstract class and that defines properties for the user profile that are not specified in the profile configuration element.