пользовательский элемент управления для мобильных устройств(An ASP.NET mobile control derived from the System.Web.UI.MobileControls.MobileUserControl class. User controls provide containers for custom controls built from other ASP.NET mobile controls)
индивидуально настраиваемый элемент управления(A dynamic Web Parts control that can be personalized and permanently deleted from a page for an individual user only. A per-user control appears on the page only when the page is in user scope. Note that a per-user control can have properties that are both user-scope and shared-scope for personalization purposes)
пользовательский элемент управления(A base control that provides a way to create a reusable custom control without having to create a new control class)