Briefly explain how server form post-back works ?
Post Back: The process in which a Web page sends data back to the similar page on the server.
View State: View State is the mechanism ASP.NET uses to keep track of server control state values that don't otherwise post back as part of the HTTP form View State Maintains the UI State of a Page View State is base64-encoded. It is not encrypted but it can be encrypted by setting Enable View Stat MAC="true" & setting the machine Key validation type to 3DES. If you want to NOT maintain the View State, contain the directive < %@ Page Enable View State="false" % > at the top of an .aspx page or add the attribute Enable View State="false" to any control.