The document discusses single page applications (SPAs). It provides an overview of SPAs, including their advantages over traditional web and native apps. SPAs use JavaScript libraries/frameworks like RequireJS and BackboneJS to manage client-side routing and maintain application state without reloading the entire page. The document also outlines a simple SPA architecture and provides an agenda for a developer practice covering SPA building blocks and a demo of a simple SPA using BackboneJS.