The Web Storage API provides mechanisms by which browsers can store key/value pairs, in a much more intuitive fashion than using cookies.
Storage objects are simple key-value stores, similar to objects, but they stay intact through page loads.  The keys and the values are always strings (note that integer keys will be automatically converted to strings, just like what object do). You can access these values like an object, or with the getItem() and setItem() methods.  These three lines all set the colorSetting entry in the same way:
The localStorage property allows you to access a local Storage object. localStorage is similar to sessionStorage. The only difference is that, while data stored in localStorage has no expiration time, data stored in sessionStorage gets cleared when the browsing session ends—that is, when the browser is closed.