Chapter 6 Data Storage
STORING DATA ASSOCIATED with an application is fundamental in nearly all applications, web or desktop. This can include storing a unique key to track page impression, saving usernames, preferences, and so on. The list is endless.
Up until now, storing data in a web app required you either to store it on the server side and create some linking key between the client and the server—which means your data is split between locations—or it would be stored in cookies.