-> When ASP.Net gets a page request, it decides whether to parse and compile the page, or there would be a cached version of the page, accordingly the response is sent.
Starting of page life cycle
-> At this stage, the request and response objects are set. If the request is an old request or post back, the IsPostBack property of the page is set to true. The UICulture property of the page is also set.
-> At this stage, the controls on the page are assigned unique ID by setting the Unique ID property and the themes are applied. For a new request, post back data is loaded and the control properties are restored to the view-state values.
-> At this stage, control properties are set using the view state and control state values.
-> Validate method of the validation control is called and on its successful execution, the IsValid property of the page is set to true.
Postback event handling
-> If the request is postback the related event handler is invoked.
-> At this stage, view state for the page and all controls are saved. The page calls the Render method for each control and the output of rendering is written to the Output stream class of the Response property of page.
-> The rendered page is sent to the client and page properties, such as Response and Request are unloaded and cleanup is done.