State Management : Session State Modes : InProc StateServer SQLServer

InProc : Stores session state on web server, this is default mode
Stores the data in ASP.net worker process
Session state is stored in the application domain memory space
State lost if aspnet_wp.exe recycles or application domain restarts

StateServer : Stores in a separate process called ASP.net state service.
Preserves information in event of web application restart
Service is independent of IIS and can run on a separate server
State service is like any other NT service with own process and memory

SQLServer : Stores in SQL Server database
Custom: Enables to use a custom data storage
Off : Session state is disabled