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 sessionStorage property allows you to access a session Storage object. sessionStorage is similar to Window.localStorage, the only difference is while data stored in localStorage has no expiration set, data stored in sessionStorage gets cleared when the page session ends. A page session lasts for as long as the browser is open and survives over page reloads and restores. Opening a page in a new tab or window will cause a new session to be initiated, which differs from how session cookies work.