ASP.Net Difference FAQs-5

1.Difference between ViewState and SessionState

S.No	ViewState	SessionState
1	View state is maintained in page level only.	Session state is maintained in session level.
2	View state of one page is not visible in another page.i.e., when user requests another page previous page data will be no longer available.	Session state value is available in all pages within a user session.i.e., The data will be no longer available if user close the browser or session timeout occurs.
3	View state information stored in client only.	Session state information stored in server.
4	View state persist the values of particular page in the client (browser) when post back operation done.	Session state persist the data of particular user in the server. This data available till user close the browser or session time completes.
5	View state used to persist page-instance-specific data.	Session state used to persist the user-specific data on the server side.

2.Difference between ViewState and ControlState

S.No	ViewState	ControlState
1	ViewState can be disabled	Control State cannot be disabled.
2	ViewState is implemented by using EnableViewState property of a control to true.	Control State works even when EnableViewState is off. To use Control State (for example in a custom control) we have to override OnInit method,call RegisterRequiresControlState method in OnInit method and then override the SaveControlState and LoadControlState methods.
3	ViewState is used to maintain page-level state for large data	Control State is used for small data only. eg: maintain clicked page number in a GridView even when EnableViewState is off

3.Difference between SessionState and Cookies

S.No	SessionState	Cookies
1	Session can store any type of data because the value is of datatype of "object"	Cookies can store only "string" datatype
2	These are stored at Server side	They are stored at Client side
3	Session are secured because it is stored in binary format/encrypted form and it gets decrypted at server	Cookie is non-secure since stored in text format at client side
4	Session is independent for every client i.e individual for every client	Cookies may or may not be individual for every client
5	There is no limitation on size or number of sessions to be used in an application	Due to cookies network traffic will increase.Size of cookie is limited to 40 and number of cookies to be used is restricted to 20.
6	For all conditions/situations we can use sessions	Only in few situations we can use cookies because of no security
7	We cannot disable the sessions.Sessions can be used without cookies also(by disabling cookies)	We can disable cookies
8	The disadvantage of session is that it is a burden/overhead on server	Since the value is string there is no security
9	Sessions are called as Non-Persistent cookies because its life time can be set manually	We have persistent and non-persistent cookies