ASP.NET page passes through a series of steps during its life cycle. Following is the high-level explanation of life cycle stages/steps.
Initialization: Controls raise their Init event in this stage.Objects and variables are initializes for complete lifecycle of request.
LoadViewState: is a post back stage and loads the view state for the controls that enabled its view state property.
LoadPostBackData: is also a post back stage and loads the data posted for the controls and update them.
Load: In this stage page as well as all the controls raise their Load event. Till this stage all the controls are initialized and loaded. In most of the cases, we are coding this event handler.
RaisePostBackEvent: is again a postback stage. For example, it’s raise against a button click event. We can easily put our code here to perform certain actions.
SaveViewState: Finally, controls state is saved in this stage before Rendering HTML.
Render: This is the stage where HTML is generated for the page.
Dispose: Lastly, all objects associated with the request are cleaned up.