These objects provide two levels of scope:
Application State
Data stored in the application object can be shared by all the sessions of the application. Application object stores data in the key value pair.
Session State
Session State stores session-specific information and the information is visible within the session only. ASP.NET creates unique sessionId for each session of the application. SessionIDs are maintained either by an HTTP cookie or a modified URL, as set in the application’s configuration settings. By default, SessionID values are stored in a cookie.