The sessionStorage object stores the data for one session. The data is deleted when the user closes the browser window.
The canvas element: Canvas consists of a drawable region defined in HTML code with height and width attributes. JavaScript code may access the area through a full set of drawing functions similar to other common 2D APIs, thus allowing for dynamically generated graphics. Some anticipated uses of the canvas include building graphs, animations, games, and image composition, timed media playback, offline storage database, document editing, drag-and-drop, cross-document messaging, browser history management, MIME type and protocol handler registration.