Difference between ViewState, SessionState and ApplicationSt

View State: 

- View state is maintained in page level only.

- View state of one page is not visible in another page.

- View state information stored in client only.

- View state persist the values of particular page in the client (browser) when post back operation done.

- View state used to persist page-instance-specific data. (Read more)

      Session State: 

- Session state is maintained in session level.

- Session state value is available in all pages within a user session.

- Session state information stored in server.

- Session state persist the data of particular user in the server. This data available till user close the browser or session time completes.

- Session state used to persist the user-specific data on the server side. (Read more)   

Application State

ApplicationState is a variable you can store values in during the life off the application (may get cycled periodically, and without your knowledge) (used less-frequently)

      Usage

- If you want to access the information on different web pages, you can use SessionState

- If you want to access from the same page, then you can use Viewstate

-Application State it's global, for all users

     Security

     Session state provides more security when compared with view state as the data value is stored in server side