The application state should usually not be saved on the client. There may be some special case in addition to the one where you write educational code and want to demonstrate how not to do it. Generally, the state of the application related to the actual use is stored in the session object or in some database. This is especially important when the application asks the user to enter a lot of data and does not want the user to lose the work if there is some hiccup in the client computer.
You spend a lot of time selecting the appropriate items in an online shop, choosing the appropriate items that work together, creating a configuration of your new model airplane, and, all of a sudden, there is a blackout in your ...
