The document discusses the evolution of real-time web technologies from early polling methods to more advanced solutions using Comet, WebSockets, and other technologies. It notes that early approaches in the 2000s using repeated polling placed too much load on servers, but that Comet and WebSockets improved this by keeping connections open to allow real-time data pushes from servers to clients more efficiently. Examples of code samples are provided for implementing real-time features using technologies like Comet, XMPP, and WebSockets.