The document discusses single page web apps, which allow a web app to exist on a single page without reloading the DOM. Key points made include: - Single page apps only update parts of the page rather than reloading the entire page, improving performance. - They allow for immediate feedback and smooth transitions between states within the app. - While they break links and expose business logic to users who inspect elements, they reduce server load and improve mobile experiences. - Popular tools for building single page apps include Backbone.js, SammyJS, and Brunch.