Web Development Summary 2: AJAX

AJAX stands for asynchronous JavaScript and XML. It is a technique for creating interactive web applications that can communicate with the server in the background without affecting the display or behavior of the page they are on. Interestingly even though they are part of the acronym neither JavaScript nor XML are required to be used for it to be AJAX.

One of the main benefits of AJAX is that it allows the page to only update the sections that change. As many web pages are virtually the same on a site using AJAX you can only update the portion that needs to change, making the page load faster. With it communicating on the background it makes it seem like the application is responding faster than it would otherwise, without changing anything on the server. It can also help reduce the load on the server since the majority of the items for the page only need to be requested once.

Because only a part of the page is updated and the browser doesn’t go to a new page the users back button will not function with it. It is also very difficult to bookmark any page other than the first one. Search companies web crawlers generally do not activate the scripting, so the updated pages will not be index for searching. If a user’s browser doesn’t support AJAX or JavaScript, or they have it disabled they won’t be able to use the functionality.