Diff between viewstate and sessionstate

viewstate is accessible for a particular page for a postback operation. it is stored as hidden variables in an encrypted form and is related to controls or can be stored in variables.user entered information in any control is persisted using viewstate.
eg : viestate("name")="Lia" -> accessible only in that page

Sessionstate is accessible across the entire web application. when a browser is exited or signed out the session variable data is lost. Sessionstate holds data pertaining to a particular user.
session("name")="Lia" -> accesible through the whole application