Can anyone explain what is the life cycle process of iPhone? i.e from the start to end of the application life cycle.
See also This post on Cocoanetics that present a very useful flowchart explaining the different calls to the AppDelegate methods during the app life cycle:

here is diagram image for understand Life Cycle (iPhone / Android)

Edit: Here is the more detailed information from Apple Docs.
Part 1:

Part 2:

Also this one is for View Controller Life Cycle methods
There's another simpler one in ios developer's cookbook

If you want to something more detail ,you can read the official document delivered by apple
It has been updated with iOS6.0
http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/ViewLoadingandUnloading/ViewLoadingandUnloading.html
来源:https://stackoverflow.com/questions/6519847/what-is-the-life-cycle-of-an-iphone-application