Ajax stands for Asynchronous JavaScript and XML. It means that you can combine HTML, JavaScript,and XML to create client Web applications that can interact with a server asynchronously. In practicalterms, it means your web page can load and send data to the server without needing to reload the page.

If you are coming from a Java POJO lightweight programming background, you may be wondering why you should have to learn a Flash-driven language when you already have thousands of productive “Java frameworks”. As I suggested earlier for the ActionScriptor, just give it a little time or one full project and you’ll reap the benefits. I have developed a lot using JavaScript and Ajax, and while JavaScript is improving day by day, it is still a scripting language. It supports just simple linear animations and it is not a strongly typed OO language.

Flex also supports vector graphics natively while Ajax has only limited support. Flex includes crossbrowser support, and much more. For example, debugging Flex is much easier than debugging JavaScript and if you fix something in one browser, you know it will be fixed in all browsers.

You can be much more productive with Flex, and produce code that is more elegant and maintainable. If you are coming from an OO environment, you will find Flex very easy to learn. If you are coming from scripting language background, Flex is likely to be harder than Ajax to learn, but you will ultimately be working in a much better environment. You will have a proper OO software design and reap all the benefits that this offers.