Web Namespaces in Visual Studio
The namespaces in the .NET Framework about ASP.NET Web applications and XML Web services include:
System.Web - contains classes and interfaces that enable browser/server communication. This namespace classes for managing HTTP output to the client (HttpResponse) and reading HTTP requests (HttpRequest). Additional classes provide facilities for server-side utilities and processes, cookie manipulation, file transfer, exception information, and output cache control.
System.Web.UI – contains classes for creating Web Form pages, including the Page class and other standard classes used to create Web user interfaces.
System.Web.UI.HtmlControls – contains classes for HTML-specific controls that can be added to Web Forms to create Web user interfaces.
System.Web.UI.WebControls – contains classes for creating ASP.NET Web sever controls. When added to a Web Form, these controls render browser-specific HTML and script to create a device-independent Web user interface.
System.Web.Mobile - contains the core capabilities, including authentication and error handling, required for building ASP.NET mobile Web applications.
System.Web.UI.MobileControls - contains a set of ASP.NET server controls that can render your application for different mobile devices.
System.Web.Services - contains classes that enable you to build and use XML Web services, which are programmable entities residing on a Web server and exposed via standard Internet protocols.