It isn’t a direct comparison, because both of these tools are intended to be used in very different situations (but often in coordination with each other). Asynchronous data updates simply mean that the server can update parts of a page with information in real-time without refreshing the whole thing. This is crucial for modern applications like live chat, video streaming, photo galleries, interactive forms, etc.
|What Is It||ECMAScript-compliant programming language for creating interactive web pages and applications||A set of technologies that allows webpages to communicate with servers, and vice-versa|
|Role||Frontend interactive UI design and scripting, web applications||Backend scripting and updating web pages without reloading them|
|How It Works||Code is interpreted by a JS engine within the browser and compiled in real-time||User interaction script triggers XMLHttpRequest to the server which sends back required data in XML/ JSON/ text format|
|Cross Browser Compatibility||Decent, some features may not work as intended since each browser has its own JS engine||Works on any modern browser that supports the XMLHttpRequest object|
Origin of AJAX
If you entered some data into the page, it would have to reload completely in order to display new information. This was quite inconvenient for the user considering dial-up internet speeds of the time (especially with pages that contained images). Sending the entire page back and forth was not an efficient means of updating data.
But Microsoft had something interesting brewing behind the scenes. You see, their Outlook email app was using a version of the Java Virtual Machine built into Windows. But Sun Microsystems sued them for not complying with standards, and Microsoft quickly ditched this technology.
But rival browsers quickly started copying this function. And to this day, XMLHttpRequest forms the core of AJAX. It was the key reason behind the success of many early web apps such as Google Mail and Google Maps.
Initially, the XMLHttpRequest function made a “call” to the web server which then sent back data in XML. Nowadays, this data can be returned in several formats- JSON, text, HTML, etc. And thanks to this little innovation, web applications became a thing.
What Is AJAX Made From?
When James Garrett first coined the abbreviation “AJAX”, he detailed a list of technologies that comprised the final framework. First, you have the XMLHttpRequest object at its core which is responsible for asynchronous communication and data exchange with the server. Modern browsers have alternatives other than this.
Now, AJAX is used for everything that requires real-time data updates from the server. Even something as simple as the autocomplete function within a search bar can’t be done without AJAX.
Granted, there are new methods for accomplishing the same tasks- like Fetch API. But AJAX itself is more of a methodology rather than a well-defined framework or language.
Comparing The Ease Of Learning
Comparing The Cross Browser Compatibility
AJAX, on the other hand, is a methodology to exchange data asynchronously between browsers. At its core is the XMLHttpRequest object, but different browsers have their own techniques to create this object. Legacy IE browsers use the ActiveXObject, but other than that any browser which uses XMLHttpRequest will work just fine with AJAX.