Question - What is ViewState ? and how it is managed ? 
          
        
        Answer - 
          ASP.NET ViewState is a new kind of state service that developers can use to track  UI state on a per-user basis. Internally it uses an an old Web programming trick-roundtripping  state in a hidden form field and bakes it right into the page-processing framework.It needs less code to write and maintain state in your Web-based forms.