one of the state management technique to resolve stateless prob of web.Storage Of Session: InProc : worker process OutProc : state server or sql serverStorage Type: InProc : All Type Data OutProc : Only Serializable

As web is stateless so to manage states ASP.net have several state management technique's.Session is one of the server side state management techniques.Type's of Session : InProc: It's stored locally in memory of ASP.NET worker process. Out Proc: It's manage by any window service or store in SQL Server Database.

We know that Http is stateless, means when we open a webpage and fill some information and then move to next page then the data which we have entered will lost. It happed do to Http protocol stateless nature. So here session come into existence, Session provide us the way of storing data in server memory. So you can store your page data into server memory and retrieve it back during page postbacks.