Learning PHP, MySQL, JavaScript, and CSS, 2nd Edition

Chapter 17. Using Ajax

The term “Ajax” was first coined in 2005; it originally stood for Asynchronous JavaScript and XML, although that phrase has become a bit outdated. In simple terms, Ajax is a web development technique that uses a set of methods built into JavaScript to transfer data between the browser and a server in the background. An excellent example of this technology is Google Maps (see Figure 17-1), in which new sections of a map are downloaded from the server when needed, without requiring a page refresh.

Figure 17-1. Google Maps is an excellent example of Ajax in action

Using Ajax not only substantially reduces the amount of data that must be sent back and forth but also makes web pages seamlessly dynamic, allowing them to behave more like self-contained applications. The results are a much improved user interface and better responsiveness.