Some Web service classes derive from System.Web.WebServices; others do not. What’s the deal?
Ans) WebService contributes properties named Application, Session, Context, Server, and User to derived classes enabling Web services to access the ASP.NET objects of the same name. If you don’t use these objects in your Web service-for example, if you don’t use application state or session state-then you don’t have to derive from WebService, either. Incidentally, if you want to use ASP.