In the previous post I looked at how webpages could be made to auto reload and auto update and by using Javascript how specific parts could be updated without the need to load the whole page.
Although the Javascript makes the webpage appear slicker the website still uses the client request method as before (the webpage still had to request new data). The Javascript just made the experience nicer. This post starts to look at true asynchronous or two-way communication where either side can send data without being asked for it. This is achieved by using websockets.