Stage management is a sub-discipline of stagecraft.

Although a somewhat fluid line of work, in essence the 
stage management team (which can consist of a production 
stage manager, several assistant stage managers, and any 
number of production assistants) is responsible for 
organizing the production, communicating across different 
disciplines (e.g., between the director and the backstage 
crew, or the actors and production management), and keeping 
everything running smoothly. This refers not only to 
seamless management of the technical aspects of a 
production, but of the human aspects as well.

By using this,we can get good performance.this is divided 
into two tyes 1.client side
              2.sever side 
in client side a.view state
               b.hidden state 
               c.query string
               d.cookies
In sever side  a.sessions
               b.applications

it is not stage management it is state management

In Asp.Net web form are HTTP-Based,That y they are stateless
means server don't whether it from same client or diffrent
bcoz all data destroyed and recreated after ever request.
so to overcome this problem we use state management.

           state Management are two types
server side-
        1)Application
        2)Session
Client Side
      1)Cookies
      2)ViewState
       3)Hidden field
      4)Query String