Web pages are recreated each time the page is posted to the server. In traditional Web programming, this would ordinarily mean that all information associated with the page and the controls on the page would be lost with each round trip.

To overcome this inherent limitation of traditional Web programming, the ASP.NET page framework includes various options to help you preserve changes — that is, for managing state. The page framework includes a facility called view state that automatically preserves property values of the page and all the controls on it between round trips. However, you will probably also have application-specific values that you want to preserve. To do so, you can use one of the state management options.

Client-Based State Management Options:
View State
Hidden Form Fields
Cookies
Query Strings

Server-Based State Management Options
Application State
Session State
Database Support